1 X Ooma Telo Handset Cordless Phone Battery 3.6 Volt, Ni-MH 700 mAh - Replacement For OOMA HB1001 Replacement Battery for OOMA HB1001 - Ni-MH, Volt, 700 mAh. 100% compatible with your OEM battery - 3 year warranty. Made with high quality Japanese cells. Synergy Digital is a Registered Trademark