Nikon D750 DSLR Camera (Body Only) - Manual (Page 225)

197
When the camera is used with optional WR-1 ( 0 444) and
WR-R10/WR-T10 ( 0 444) wireless remote controllers, the
shutter-release buttons on the WR-1 and WR-T10 perform the
same functions as the camera shutter-release button, allowing
remote continuous and self-timer photography.
WR-1 Wireless Remote Controllers
The WR-1 can function as either a transmitter or a receiver and is
used in combination either with another WR-1 or a WR-R10 or
WR-T10 wireless remote controller. For example, a WR-1 can be
connected to the accessory terminal for use as a receiver,
allowing camera settings to be changed or the shutter to be
released remotely by another WR-1 acting as a transmitter.
WR-R10/WR-T10 Wireless Remote Controllers
When a WR-R10 (transceiver) is connected to the camera, the
shutter can be released using a WR-T10 (transmitter).
Wireless Remote Controllers