Coolkiller PolarBear vs MMD KM21 Ultra
Get the Coolkiller PolarBear for the 1,500 mAh battery. Get the MMD KM21 Ultra for knob.
The differences that matter
Skip the 40-row spec sheet. These are the specs that change how each board feels, sounds, and fits your desk.
Coolkiller PolarBear
MMD KM21 Ultra
Connection
Wired, Wireless
Bluetooth, 2.4 GHz, Wired
Battery
1,500 mAh
980 mAh
Case material
Plastic
Aluminum
Mount style
Gasket Mount
Top Mount
Knob
No
Yes
- Coolkiller PolarBear
- MMD KM21 Ultra
- Performance
- 6067
- Build quality
- 6182
- Productivity
- 7289
- Customizability
- 5589
- Portability
- 8786
- Layout size: Numpad
- Hot-swappable
- Sound dampening
Coolkiller PolarBear vs MMD KM21 Ultra specs
Every tracked spec, side by side. Rows marked with a dot differ between the boards.
10 of 23 specs differ
Coolkiller PolarBear
MMD KM21 Ultra
Switch options
Hot-swappable
Mount style
Sound dampening
Layout size
Layout standard
Ergonomics
Knob
Display
Connection
Battery
USB-C
Case material
Plate material
Keycaps
Weight
Dimensions
Backlight
QMK
VIA
N-key rollover
Mac & Windows
Released
Compare prices
Live prices from the stores we track, cheapest in-stock offer first.
Prices in USD are converted to your currency and can change at any time. KeebFinder may earn a commission when you buy through these links, at no extra cost to you.
Not sold on either?
![[In Stock] Soso-pad Customizable Wireless Fingerprint ID Numpad](https://cdn.shopify.com/s/files/1/1674/0405/files/Soso-Pad_3-3.jpg?v=1772105505&width=3840&quality=75)
Still torn?
Answer a few quick questions and the keyboard finder ranks 2,000+ boards by how you will actually use yours.