Arrived to install Uv previously approved by the homeowners. Cut the hole in the return for the bulb to protrude into the duct. Mounted the ballast (mount for the bulb) over the hole. Installed Uv bulb in the ballast and duct. Ran wire to power the uv system, making sure to wire it in so it only turns on when the furnace is moving air. Tested system operations. Furnace and Uv are functioning properly at this time.