Godox 16 Channels Wireless/radio Studio Flash Trigger with Receiver Set Rt-16 for Canon Nikon Pentax Slr Camera 1.This wireless trigger is control discreteness for camera to trigger hot shoe flashgun synchronously. 2.Easy installation, low power consumption. 3.No any damage to camera. 4.High-speed and synchronous for 1/200 second. 5.Max. working distance: 30M (open area, without interference). 6.16 channels to avoid interference. 7.The receiver has an on/off switch, and an LED to indicate triggering. 8.New design: Channel Selector outside the transmitter and the receiver.