Vello FreeWave Wireless Remote Shutter Release for Sony Alpha Cameras 16 Million Possible Channels | Operates on Radio Frequencies (RF) | Receiver has Dedicated Sony Shoe Direct Line of Sight Not Required | Operating Range up to 320' (100 m) | Wireless Continuous or Single Exposures Long Time Exposures | Transmitter Can Fire Multiple Receivers | Wireless Autofocusing & Triggering Whats In The Box: Wireless RF Receiver, Wireless RF Transmitter, 23A 12V Battery for Transmitter, CR2 3V Battery for Receiver, Lanyard, Clip, User's Manual, 1-Year Limited Warranty