This circular vent cover (RAM-VENT-RNDU) for the RAM Vent-Temp temperature module accessory installs to the 50" hose that comes with the RAM Vent-Temp kits. Add or replace this vent cover to accommodate the shape of your vehicle's A/C vent for optimal air flow when installed. This vent cover covers a surface area of 3.67" in diameter, and includes zip ties to secure to your vent.