LiPO 3.7V 720MAH BatteryReplacement battery for: ET 400 402 Handheld Transmitter ET 800 802 Handheld Transmitter UL 1200 1202 Handheld Transmitter WF 1200 1202 Handheld Transmitter EZ 900 902 903 904 Handheld Transmitter PE 900 902 903 Handheld Transmitter RX 120 Collar Receiver Note: If you have an RX 090 Collar Receiver you will need the LIPO 3. 7V 300MAH BATTERY Model will be located in between the two contact points of the collar receiver and under the rear skin for the