COSMOS II - 25th Anniversary Edition

To celebrate Cooler Master’s quarter-century birthday, the brand introduces the COSMOS II 25th Anniversary Edition. A tribute to Cooler Master’s original and iconic COSMOS case. This special edition features an updated streamlined design with dual curved tempered glass side panels accentuated by two distinctive brushed aluminum handles. The smooth, brushed aluminum touch of the front and top panels refresh the case with an updated design, while the curved tempered glass side panels can unlock and swing open like on a luxurious race car. Moreover, the case has been updated with an aluminum motherboard tray and partition plate for an even more premium touch.


The Ultra Tower

25th Anniversary Edition

Awards and Reviews

Curved Tempered Glass

Innovative dual curved dark glass

Ever since the launch of the original Cosmos II, fans have been asking, or making by themselves, for a windowed side panel.
Cooler Master has accepted the challenge and to celebrate the 25th anniversary we have released this special edition.

For this special edition we even take it a step further:
Both sides come with beautifully crafted curved tempered side panels that blend seamlessly with the sophisticated contours of the case.

A Legacy of Aluminum

The first aluminum chassis was made by Cooler Master under the ATCS series. This 25th anniversary edition of Cosmos II is paying its tribute by changing the M/B Tray & Partition Plate to aluminum. Plus it adds a touch of premium.

Aluminum Motherboard Tray with black rubber grommets

Aluminum Partition Plate with black rubber grommets

Sturdy Steel Frame

A Touch of Premium

This special edition features an updated design with two distinctive brushed aluminum handles and a soft brushed aluminum sheen on the front and top panels. The top slide panel covers the Advanced Control Panel and hidden behind the front slide panel lies a stack of hot-swappable drive bays.

  • 1. Solid brushed aluminum handles
  • 2. Solid brushed aluminum covered top
  • 3. Solid brushed aluminum front panel


Blue LED Ambient Lighthing

When thinking about the cosmos, the color blue will spring to mind. Blue is also the color first used in our chassis. This chassis will bring back that feeling and it will emphasize the beauty of your components with a discrete blue glow from the front LED fan and strip displayed through the tinted tempered glass panels.

Streamlined Airflow

Individual cooling zones make sure you have an improved thermal management and a streamlined airflow. With a 200mm blue LED fan in the front and a 120mm fan in the back you are already certain from a quiet cooling performance.

Model number RC-1200-KKN2
Available Color(s) Silver / Black
Materials Appearance:
Aluminum, Mesh, Plastic
Steel, Aluminum
Side panel:
Tempered Glass
Dimensions (WxHxD) 344(W) x 704(H) x 664(D) mm
Weight 23kg
5.25" Drive Bays 3
3.5" Drive Bays 13 (2 from X-dock with key locks, 5 HDDs in the middle cage, 6 HDDs in the bottom cage)
2.5" Drive Bays 11 (converted from 3.5" cages)
I/O Panel 2x USB 3.0
4x USB 2.0
1x Audio In & Out
Expansion Slots 10+1
Air Cooling Compatibility Top:
1x 200m or 2x 140mm or 3x 120mm
1x 200mm or 1x 120/140mm
1x 120/140mm
3x 120mm
Water Cooling Compatibility Top:
120/140/240/280mm radiator, max. 320mm long
Included Fans Top:
1x 120mm
1x 200mm Blue LED
1x 140mm
3x 120mm
Power Supply Type Bottom Mount
Standard ATX PS2 / EPS 12V
Maximum CPU Cooler Height 190mm
Maximum GPU/PCI Card Length 385mm
Warranty 2 years
EAN Code 4719512057445
UPC Code 884102031076