APPLICABLE: For use with for Valve Index Controllers, for HTC Vive Controllers, for HTC Vive Tracking, for VR Ink Pilot, (NOT FOR REVVL 4 PLUS). WITH USB EXTENSION CABLE: USB dongle receiver allows you to use for HP Reverb G2 headset and for Valve Index Controller, comes with USB extension cable. SMALL AND PORTABLE: For Steam VR USB dongle receiver is tested before shipping to ensure it functions perfectly. Small and light, easy to carry. PRE INSTALLED FOR WATCHMAN FIRMWARE: USB dongle receiver comes pre installed with for watchman firmware and functions similarly to the for Steam controller. PLUG AND PLAY: USB dongle wireless receiver is plug and play, just plug it into your computer and the necessary drivers will be installed automatically.