Digital Voltmeter and Tachometer (DVT™) combines a digital voltmeter with a built-in load for 4 and 5 cell receiver packs and a 9.6 volt transmitter battery pack with a tachometer that accurately reads rpm in 10 rpm increments for 2, 3, or 4 bladed props. Features: - Tachometer measures from 0-29,000 rpm - Automatically turns off after two minutes, if not in use - Measures voltage for all Tx and Rx packs (Futaba, Jr, Hitec) - 240mAh load on 4 cell packs, 300mA load on 5 cell Rx packs - 400mAh load on 9.6 volt transmitter packs - 9V battery included with low battery indicator