Our L.E.D. Battery Gauge is an array of L.E.D. s indicating the operating voltage of the bike s electrical system. Green L.E.D. s represent the normal operating range of your charging system, 12.5v to 14.5v. Amber L.E.D. s warn the rider that the bike is not charging. If the reading drops below 10v or exceeds 15v, a flashing red L.E.D. will alert the rider of an impending stall orthe possibility of damage to the battery &/or sensitive electronic components on the motorcycle. Simple two-wire connection & a compact size (about 2 x 3/4 x 3/16 ) make installation a breeze. A daylight sensor automatically adjusts the brightness of the L.E.D. s.