Premium Power Pack - Nitecore D2 Digicharger Smart Universal Charger with Car Adapter, 2x Nitecore 3400mAh 18650 Rechargeable Protected Battery and Bright Lumentac Keychain Light Fully automated with overcharge, undercharge and reverse prolarity protection;Automatically detects battery status, selects appropriate charge mode and stops when complete 48% more capacity than typical 18650 battery; Designed for Nitecore high performance LED flashlights; works for all LED Flashlights that use 18650 Nitecore D2 compatible with Li-ion 26650 22650 18650 17670 18490 17500 17335 16340 (RCR123) 14500 10440 Ni-MH/Ni-CD: AA AAA A SC C Rechargeable batteries Digital LED displays detail charging mode, progress, voltage, current for each battery 500 charge cycles, save money and environment