Yongnuo RF-603 N3 2.4GHz Wireless Flash Trigger/Wireless Shutter Release Transceiver Kit for Nikon D90/D3100/D5000/D7000 Works as a wireless shutter release control to trigger your camera Transceiver System - works as a wireless flash trigger and receiver Each RF-603 is designed to work as trigger and as receiver Compatible with Nikon D90/D3100/D5000/D7000 Series cameras for shutter release control Includes (2) RF-603 transceivers (1) N3 shutter release cord