This module is an external dc-dc booster; it draws dc voltage from 1s li po battery, boosts it to 6v for your receiver & servo, and keeps providing the stable output current of 3amp or above. As the bec voltage of 1s li po, which used by 1/12th scale race cars, usually goes below 4. 2v and causes the receiver and servo to work abnormally, so a separate battery is needed to power the receiver. This booster can work as a receiver battery and save you the trouble of battery charging and maintenance. Part number 30601000 specifications input voltage: 1s lipo?3-4 cell nimh output voltage: 6v output current(cont. /peak): 3a/6a size: 28. 0x26. 8x11. 8mm (lxwxh) weight:10. 2g (hw30601000)