Features two private-coded channels, compatible with additional Wein Pro-Sync receivers on channel-1 or channel-2. Allows you to switch between two pre-set remote lighting setups without leaving the camera position by simply changing the channels at the transmitter. Also allows two photographers to use separate Pro-Sync systems in the same area with signal interference. Also features in-line PC hookup for on-camera flash, plus transmitter selector switch for independent on-camera flash/remote flash control. Excellent for flash bracket users. Pro-Sync 2 System Includes one transmitter and one receiver.