The UT-1 Communications Unit/WT-5A Wireless Transmitter combination, when connected to the D810, D810A, D800, D800E, D750, D7200, D7100 or D7000 DSLRs, allows the camera to connect wirelessly to a computer or FTP server for downloading of images, in addition to controlling the camera remotely using Nikon’s Camera Control Pro 2 software.
The UT-1 is powered by an EN-EL15 Li-ion rechargeable battery; It can also be powered by the optional EP-5B power connector and EH-5b or EH-5/EH-5a AC Adapter.
The UT-1 (with the WT-5 attached to it) attaches to the DSLR via the accessory hot shoe, or the optional SK-7 bracket.
To use the UT-1 with a D7100, use the UC-E6 USB cable, which is provided with the camera, to connect the UT-1 with the D7100.