About this item Can be applied to various 3.7V lithium core. High-accuracy voltage detection circuit, fine workmanship and durable, compact size and lightweight. Over-discharge protection, overcurrent protection, overcharge protection, short circuit protection functions. Built-in three-stage over-current detection circuit (over-current 1, over-current 2, or load short circuit). Applicable to: vacuum cleaner, massager battery pack, LED light backup power supply, 12V electronic products, solar street light battery pack, monitoring standby power supply, etc. Product dimensions: 2.09 x 0.67 x 0.16 inches.