Perun AB is a microcontroller-steered mosfet device with active brake and Li-Po protection which can be turned on or off. It is very rugged and powerful, yet compact. Microcontroller guarantees resistance to contact bouncing. Active brake (AB) prevents spring wear and double shots in semi mode in replicas with high rate of fire. Li-Po protection uses sound signals to let you know, that your Li-Po baterry is running low and you should replace it.