Spektrum Voltage Protector.#SPM1600 Features: For DSM system Prevents voltage drops to receiver Plugs into any open channel slot Notes: Spektrum's new Voltage Protector prevents a DSM receiver's voltage from dropping below the proper operating level in lower voltage applications such as 4-cell 1/12 carpet racers.Installation is as simple as plugging it into an open channel slot on the receiver unit.This Voltage Protector is not intended for Aircraft use.