Nikon's WR-T10 Wireless Remote Controller Transmitter is a remote control transmitter designed to work with the Nikon WR-R10 Wireless Remote Controller transceiver (available separately): together, they control the shutter release on Nikon DSLR cameras wirelessly. The WR-T10/WR-R10 units use radio frequencies to communicate--you can trigger any number of Nikon DSLR cameras equipped with WR-R10 units, using one WR-T10 controller.