Easy installation; Sufficient accessories; No additional tools required; Time-saving and effortless; RL-BI004 battery indicator with hour meter. It can work on most lead-acid storage batteries. It has a powerful battery indicator system and timing system, as well as another unique function. Battery indicator system including: delay display function, power-off memory function, open circuit reset function, etc. Timing system including: total running hours accumulation, total hours resettable, etc. br 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 +/- 1-3 cm.