Site Information

  • Image 1
  • Black exterior and red interior and ventilated front cover with 140.2 (280) mount.
  • Black exterior and white interior and ventilated front cover with 140.2 (280) mount.
  • Black exterior and gunmetal interior and ventilated front cover with 140.2 (280) mount.
  • Gunmetal exterior and red interior and ventilated front cover with 140.2 (280) mount.
  • Gunmetal exterior and black interior and ventilated front cover with 140.2 (280) mount.
  • Gunmetal exterior and white interior and ventilated front cover with 140.2 (280) mount.
  • White exterior (only available during limited runs) and red interior and ventilated front cover with 140.2 (280) mount.
  • White exterior (only available during limited runs) and black interior and ventilated front cover with 140.2 (280) mount.
  • White exterior (only available during limited runs) and gunmetal interior and ventilated front cover with 140.2 (280) mount.
  • Shown with ventilated front cover and 140.2 (280 mount)
  • Shown with ventilated front cover removed and 140.2 (280 mount). Great access for cleaning fans!!
  • Shown with ventilated front cover removed and 120.2 (240 mount) in upper position. Great access for cleaning fans!!
  • Shown with solid ventilated front cover removed and 120.2 (240 mount) in lower position. Great access for cleaning fans!!
  • S3 with Standard Ventilated Top, Flex-Bay front cover with 120.2 (240) Flex-Bay Fan/Radiator Mount, and Standard Windowed Side Cover.
  • S3 with Standard Window Side Cover
  • S3 with XL Window Side Cover
  • S3 with Window/Ventilated Side Cover
  • S3 with Solid Side Cover
  • S3 Rear
  • S3 Rear Chassis
  • Image 22
  • Image 23
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  • Motherboard Plate
  • Removable S3 Motherboard Plate
  • S3 Drop-in Top Chassis
  • Drop-in Chassis with Optional 240/280 Universal Mount
  • Solid Top Panel with Window Side Cover
  • Full Window Top Panel with Window Side Cover
  • Standard Ventilated Top with Solid FlexBay Covers
  • Standard Ventilated Top with Ventilated FlexBay Covers and Window Side Cover.
  • Extended 31mm Top, Solid Flexbays, Window Side Cover
  • Standard Ventilated Top with Ventilated Flexbay Covers, Window Side Cover and USB/HD Audio I/O
  • S3 Front Chassis
  • Large GPU compatibility

Mercury S3 Case - Customizable

$299.95 $199.95
(You save $100.00)
Calculated at checkout

Out of Stock

Product Description

*** Case orders have been temporarily suspended while we deal with our current backlog. We hope to reopen them soon. Accessory items are available to order. ***



The Mercury S3 is a versatile mITX PC Chassis that enables the use of multiple radiators.  

The Mercury S3 now includes the SSD Stealth Mount for the motherboard tray, and 5/16" (8mm) nut-driver for drive cages and windows! 


Mercury S3 Case Features: (click the links below for full desrciptions)



Technical Specs  
Flex-Bays (5.25 bays) 7
PCI Slots 3
Motherboard tray size (width x height) 6.57" x 7.69" (167mm x 195mm)
Native HDD Locations 2
Native SSD Locations 4
Total possible HDD locations with extra HDD cages (using additional mounts, purchased separately) 9
Total possible SSD locations with extra SSD mounts (using additional mounts, purchased separately) 18
PSU Mounting locations 1
Weight (Pounds) 10
Optional Front I/O Panel Yes
Compatible Motherboard Form Factors  
mITX Yes
mATX -
E-ATX (dual CPU) -

Exterior (width x depth x height)

(dimensions shown are for the case only. Rubber feet add .75’’ (19mm) to height, optional standard casters add 2.6’’ (67mm) and HD Casters add 3’’ (76mm))

10.54" x 15.03" x 14.94" (268mm x 382mm x 379mm)
Maximum Radiator/Fan clearance above motherboard tray with standard height top cover 90mm
Cooling Tower Clearance (air cooler) 200mm


Note: Exterior dimensions shown are for the case only. Rubber feet add .81’’ (21mm) to height



Case Features and Included Accessories  
All Aluminum construction Yes
Flex-Bay System Yes
Accessory mounting System -
Quick Release Exterior Yes
Flex-Bay 5.25 Device Mounts - Standard (MAC-125) 2 sets
Flex-Bay 5.25 Device Mounts - Short Adjustable (MAC-213) 1 set
Integrated Radiator Mounting (beyond 120.1/140.1) Yes (optional)
Drop-in Top Radiator Mounting Yes (optional)
Drop-in Side Radiator Mounting -
Side Radiator Mounting -
Isolated Cooling Chambers -
Dual Chamber Design -
Reversible -
Slide out motherboard tray with tech station conversion kit -
Anti-Vandal style power and reset switches with MDPC-X sleeved cables Yes
Included PSU support mount -
Compatible Radiator Sizes (may require additional mounts)  
120.1 - 120.2 (120 - 240) Yes
140.1 - 140.2 (140 - 280) Yes
120.3 (360) -
140.3 (420) -
120.4 (480) -
140.4 (560) -
120.9 (1080) -
140.9 (1260) -
180.3 (540) -
180.4 (720) -
Shipping Format: Domestic  
Flat Packed -
Fully Assembled Yes
Shipping Format: International                  
Flat Packed Yes
Fully Assembled No




S3 specific case accessories (Included in Limited Run Mercury S3's)


 S3 Stealth SSD Mount


Product Reviews

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Previous | Showing reviews 11-20 of 33 | Next

  1. Compromise Nothing!

    Posted by Frank McDermott on 26th Jan 2015

    This is my first CaseLabs case and all I can say is: This case is a dream. The modularity of the flex-bay system, as well as all of the panels, is nothing short of fantastic. If you can think of a way to mount something, CaseLabs has a solution in their wide array of accessory mounts and configuration options.

    The aluminum construction is thick enough to feel like a high quality build (and it is!), but not too thick that it's tough to mod. Extremely mod friendly. I was extremely hesitant to start modding this case, but was eased when I realized every part of this case can be removed and replaced; Something that surprised me. If you're going to be modding, and want a monster case without the monster size, this is the case for you. At one point I had two radiators (a 120 and a 240), four case fans, a pump, reservoir, CPU/GPU/RAM blocks, a full-size GPU, and a fan controller in an mITX case! Although I remove two of the case fans and the 240 radiator to mount the reservoir on the top of the case, for better ascetics.

    I found the case to be fairly roomy for it's size, though this is far from a complaint as you expect that with an mITX case. With a full loop it was tough to work in, but being as mod-friendly as it is I was able to achieve the compact look I wanted without having to compromise. The ability to completely tear-down the case is what makes this such a dream for modding.

    The support team at CaseLabs is awesome.
    Upon submitting my order with a two-tone paint scheme, a representative emailed me asking specifically which components I wanted to be painted each color (with some very minor restrictions). Had exchanged several emails until we were both sure that we had the same idea in mind and two weeks later I received precisely what I wanted (with loads of extra hardware!).
    Due to my own error I ordered a couple of incorrect accessories, which the Support Team had no problem helping me with.

    When I first saw the price tag, I was a little taken aback... but after completing my build and having the experience I did, I realize that the price tag includes way more than just the case. From start to finish, this is a fantastic case. I would proudly recommend this case (and CaseLabs, in general) to anyone and everyone!

  2. Superb Case!

    Posted by Unknown on 30th Dec 2014

    Highly recommend this case if you are looking for a mini-itx case. Excellent fit and finish.

  3. Best Mini-ITX Gaming Case

    Posted by Shukero on 4th Dec 2014

    This is a GREAT option if you want a mini-ITX Gaming case, but want some space to move around in; this is your case. I love the craftsmanship! Total quality, I'd buy this again in a heartbeat.

  4. Top quality & performance

    Posted by jellymould on 8th Nov 2014

    From initial engagement with questions and queries to final purchase, delivery to UK and build of my Caselabs S3 I have been immensely impressed.
    I did a lot of research as this was my first full build and I would recommend that you don't waste your time looking anywhere else for a PC case - Caselabs is your answer!

  5. Hands down:

    Posted by Happy Customer on 23rd Sep 2014

    The best case I've come across so far!

    - Very good overall build quality (thick but light aluminum, very sturdy)
    - Outstanding engineering job (assembly, case features, etc.)
    - Beautiful and well done coloring
    - Nice packaging, spare parts and other accessories
    - Decent manual

    - I also had good customer support
    - and the delivery (to europe) was quite fast, actually

    I have not yet put any hardware inside the case but I'm pretty sure that it will once more be a great experience!

    Thanks, CaseLabs!

  6. Fantastic

    Posted by Unknown on 10th Jul 2014

    This case is..The Bomb! Fantastic case hands down the best.

  7. Nearly perfect

    Posted by bryan on 24th May 2014

    10 times better than the BitFenix Prodigy that it replaced. Quality as good or better than Lian Li cases.

    Not enough holes for casters (only one predrilled hole per corner) so you have to either mod the case yourself or live with casters that loosen and spin over time.

    [CaseLabs: The S3 does not have caster mounts, so that would be the source of your problem. The S3 pedestal does however. Thank you]

  8. Immense Value, Even for the Budget-Conscious

    Posted by Unknown on 3rd May 2014

    The Case Labs Mercury S3 case exceeded my expectations on all fronts. I could not be happier with this purchase. I had the luxury of time in designing and building a gaming machine for my return to gaming after a hiatus of about 10 years. My approach was one of overall balance and value. I wanted the most bang for my buck, and as such I ran the numbers to find the highest performance/price ratio. This even included a cost average over time to factor in the different power consumption rates of components using local electric rates, etc. Using this approach I rested upon the Mercury S3 as my case of choice. The quality, durability, and thermodynamic superiority of the case means that over its lifetime it is a far better value and will save me more money than an inferior quality case would. The ability to modify the case as my needs change in the future greatly increases the value of a Case Labs product. I am blown away not only by the quality and design of the case, but by how much it exceeded my expectations.

  9. Best Enthusiast ITX case!

    Posted by Tom on 18th Mar 2014

    Hands down the best ITX case on the market! Best for water coolong and showing off a great build! I originally had the bitfenix prodigy thinking it was the best ITX case but I was wrong by a far shoot! This case is large enough for most of any water cooling set ups possible, can hold enough hard drives, and shows of my internal system just great. Shipping was great everything came wrapped in thick plastic and just opening it was amazing. Only flaws ( but really flaws) some minor paint bumps in spots not noticeable when put all together, and the HHD and SSD mounts are not very well positioned for non custom cables, I would of liked to SSD tray and HHD tray switched just so I could route my cables nicely and have my SSD name brand upright. The price was also very unpleasing I would of liked more SSD/ HHD capacity (instead of buying the optional bigger trays) and filters for intakes. But the high price means that the quality of the case is outstanding! I wish I knew of case labs before I ever thought the bitfenix prodigy was the best ITX case. Due to its high price not very any people have reviewed the case, I was surprised when I searched my favorite computer blogs to see no case lab reviews. Great job case labs no one has done it better than you!

  10. The best mini-ITX water cooling case available

    Posted by Jon on 8th Feb 2014

    This is my fist CaseLabs case and I am very satisfied with it. The other reviews are very detailed so I will just briefly mention my biggest pros and cons:

    Pro: Beautiful, solid all-aluminum construction. My previous cases have been made of steel and plastic with only bits of aluminum here and there. It was truly amazing to work with an all-aluminum case for the first time.

    Pro: Tool-less removal of exterior panels. Sometimes they can be a bit tricky to get off, but it's an infinitely better solution than using screws like most cases.

    Pro: Can fit a ton of watercooling gear. I have two 45mm thick 120.2 radiators, a D5 pump and a 150mm tube reservoir in my case. You've got lots of room to work inside.

    Pro: 100% made in the USA. It's probably the first computer product I've owned that is actually made in my country, and that does mean something to me.

    Con: No built-in dust-filter system. This is a big con for me as I am fanatical about keeping dust out of my case. Yes I know Demcifilters has a filter kit for this case, and that's what I bought. But it is not an elegant solution (especially for the 120.2 Flex Bay) and adds to the overall cost of the case. I know the brilliant minds at CaseLabs can come up with a better integrated solution, and I hope they do.

    Con: No active airflow to the hard drive area. High-performance HDDs may get very hot. My WD Black gets over 50C while gaming!

    Overall, this is an excellent case and has made a believer out of me. When I am shopping for a new case in the future, I will be considering CaseLabs first before all other manufacturers. The Mercury S3 is not a perfect product, but nothing ever is. It is, however, the best case I have owned to date.

Previous | Showing reviews 11-20 of 33 | Next

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