my speedo runs 2s perfectly
specs
1.1 Output: Continuous current 120A, burst current 760A.
1.2 Input: 4-9 cells NiMH/NiCd or 2-3 cells LiPo.

1.3 BEC Output: 5.75V@3A linear mode built-in BEC.

1.4 Resistance: 0.0003 Ohm.

1.5 Motor Supported: Sensored brushless / Sensorless Brushless.

1.6 Suitable Brushless Motor:
With 2 cells Lipo or 4-6 cells NiMH, 1/10 on-road: >=3.5T, 1/10 off-road: >=5.5T
With 3 cells Lipo or 7-9 cells NiMH, 1/10 on-road: >=5.5T, 1/10 off-road: >=8.5T
1.7 Suitable Car:
1/10, 1/12 on-road or off-road cars / trucks for competition race.
1/10, 1/8 rock crawler.
1.8 Size: 43mm(L) * 36mm(W) * 33mm(H).
1.9 Weight: 105g