RadioPopper Jr2 Studio Set II for Nikon Camera, Includes Transmitter and 2x Receiver, 902-928MHz RadioPopper Jr2 Transmitter - 2x Jr2 Receiver - Cable - RadioPopper 1 Year Limited Warranty Compatibility: Nikon Camera Battery: Transmitter and Receiver: Two "AAA" Size Batteries Battery Life: Transmitter: Approx. 20 Hours total power-on time.Receiver: Approx. 8-10 Hours total power-on time Radio Frequency: Transmitter and Receiver: 902-928Mhz, ISM Band (CE version: 868-868.6Mhz)