Pixel RW221 S1 Wireless Shutter Release Remote Control for SONY: DSLRa900, a850, a700, a560, a550, a500, a450, a400, a350, a300, a200, a100, a77, a65, a57, a55, a35,a37, a33 / Konica Minolta: DIMAGE a2, a1, 9, 7Hi, 7i, 7, 5, 4, 3, DYNAX 7D, 5D 1.It can remotely control the camera to take photos and support single shot, B door shooting. 2. Two pcs of battery working time is up to 400 hours, which is 5X save power compare with the similar product. 3.Using FSK 2.4 GHz wireless controls system which more reliability and stability. 4.Transmission distance: Max. 100 meters. 5.Communication channel: 16 channel. Using AAA battery, its easy to buy and affordable.