Hobbico Voltwatch Battery Monitor for 12V Field Power A quick way to check Field Battery levels. Features push button operation with red, amber, and green LEDs to show voltage range from 11-13V. Draws amazingly low current - less than 30mA. Easily mounts on the outside of a Field Box with included double sided tape. Wires are pre-stripped and tinned for easy soldering to battery. A quick way to check Field Battery levels Mounts on outside of Field Box with included double sided tape Push button operation One VoltWatch Battery Monitor for 12V Field Batteries One 1x1.5 piece of double-sided servo tape Important] Unit may fail if input leads are connected in reverse and the button is pushed; Be certain to observe proper polarity