From The FunKey Wiki

Differences between the Keymu and the later FunKey branded systems include the use of the Intel Edison's built-in eMMC memory for data storage rather than a microSD card, the lack of a speaker in the original prototype (though its open sourced specifications allowed for the inclusion of one), a lower maximum resolution of 128 by 128 pixels, smaller buttons, and a lower-capacity 220 mAh battery. Features only implemented in the later FunKey S and not in the Keymu or FunKey Zero include a magnetic "sleep-mode" mechanism, a protective glass layer above the display, a Menu button, 50 rather than 20 FPS, no screen tearing, and an improved hinge.

Table[edit source]

Name Keymu FunKey Zero FunKey S
alt:Image of the Keymu
alt:Image of the Keymu
alt:Image of the FunKey Zero
alt:Image of the FunKey Zero
alt:Image of the FunKey S
alt:Image of the FunKey S
Dimensions 1.65" x 1.81" x 0.67"
42 x 46 x 17 mm
~3.45" x ~1.79" x ~0.32"
~87.6 x ~45.5 x ~8.1 mm
1.67" x 1.75" x 0.54"
42.5 x 44.5 x 13.8 mm
Mass N/A 1 oz
30 g
Display 1.5" (38.1 mm) 128x128 OLED 1.54" (39.1 mm) 240x240 LCD IPS
Processor Atom 2-Core @ 500 MHz ARM Cortex-A7 @ 1.2 GHz
RAM 1 GB (LPDDR3) 64 MB (DDR2)
Refresh rate 20 FPS 50 FPS
Maximum storage 4 GB (eMMC) 2 TB (microSD)
Audio ∅11.7 mm mono at 700 mW
(missing from the initial prototype)
∅10 mm mono at 500 mW ∅10 mm mono at 500 mW
Headphone jack
Battery 220 mAh lithium-ion None (prototype) 410 mAh lithium-ion