"Lumenier F390-20A BLHeli ESC OPTO (2-4s) Ultra lightweight, compact size. Convenient motor wire solder pads. Prefaced with Bhili Firmware. Powerful F390 Chip. DSP Processing. Efficient IC reduces heat output. Includes lightweight heatsink for cooling of the FETs. 2-4s Lipolysis. OPTO ESC. Constant: 20 Amps. Burst: 30 Amps. Dimensions: 28x12x5mm. Weight: 6g (with wires).