Kastar Magic Battery can be charged w/ Micro USB with 5Volt 2A adapter: i) A USB battery, directly provides high-speed charging from the wall and on-the-go! Convenience at your finger tips; ii) Easily know the battery status when you charging the battery with LED Lights on the battery; Red color: Charging; Green color: fully charged Specification: Battery Type: Lithium-ion; Battery Voltage: 3.7V; Battery Capacity: 2600mAh. Safe to Use: Kastar lithium-ion battery cells meets UL1642 & CE safety standards to ensure that your battery pack will be safe to use as a replacement for your unit. Comes with built-in over-charge, over-discharge, over-voltage, over-current, and over-heating protection circuit. Save Money & Time: Do not spend too much time and money on frequent brands with low quality replacement. With our longer run time & protection features, your cycle life will also be improved because you get quality product for your device. Package Includes: 3-Pack Batteries Compatible with: Fenix Flashlight Battery with Micro-USB ARB-L18-2600U