HQRP Telephone Battery for Panasonic KX-TG5664 KX-TG5672 KX-TG6500 KX-TG6502 KX-TGA450 KX-TGA520 Cordless Phone System plus Coaster HQRP&reg; Battery plus HQRP&reg; Coaster; Battery Voltage: 3.6V; Capacity: 850 mAh; Ni-Mh; Nickel Metal Hydride battery pack; Compatible with Original Battery; 1 Year warranty!