Easy installation; Sufficient accessories; No additional tools needed; Time saving and effortless; RL-BI004 Battery Indicator with Hour meter. It can work on most lead acid storage battery.It has a powerful battery indicator system and timing system, as well as some other unique function design. Battery Indicator System Including:Delay Display Function,Power off Memory Function,Open Circuit Reset Function,etc. Timing System Including: accumulating total running hours TOT, total hours resettable RESET, etc. Unique Design Including: easy SNAP-IN installation,data stored automatically after diaconnecting with the battery,etc. Colour: black Material: ABS Package Contents: 1 * Power meter 2 * insert spring 2 * sheath 1 * Instruction manual Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.