The Opteka FF-1X USB Follow Focus Controller allows you to adjust focusing, start/stop video recording, control digital zoom and enable live-view remotely from Canon's built in USB protocol to enhance your HD filmmaking experience. The FF-1X is compatible with the Canon EOS 1D MK IV, 1D X, 5D MK II, 5D MK III, 7D, 60D, 500D, 550D, 600D, Rebel T1i, T2i & T3i DSLRs.

Specifications
Connectivity: USB (uses cable included with camera)
Power Source: 2 AA Batteries (not included)
Battery Life: Approx. 50 hours
Construction: Aluminum, ABS Plastic
Rig/Tripod Mount: 1/4"" thread
Dimensions (LxWxH): 2.9 x 2.9 x 2"" (73 x 73 x 50mm)
Weight: 2.75 oz (75g)