JR-2S: 9.6 volt Transmitter battery pack for JR - choose Capacity.
Transmitter Battery Kit (825 And 1225 Series) - Store | SportDOG
Amazon.com: Oceanic Transmitter Battery Kit for the OC1, OC1-LE, VT Pro, VT3, VT4.0, VT4.1, Atom, Atom 2.0, Atom 3.0, Atom 3.1, Datamask and Aeris Compumask Scuba Diving Computer : Electronics