The Gallo Gun Cannon is an inflatable drain opening accessory specifically engineered to quickly and easily clear clogged ¾˝ PVC condensate drain lines through the existing ¾˝ tee. Simply drop the Cannon into the cleanout/vent tee on your drain line, push the trigger, and the Cannon will inflate creating an airtight seal while instantly clearing the clog in your drain line. Designed to be used exclusively with the Gallo Gun 4179-01, the Cannon works with vent opening, access fittings, or tees installed on the HVAC drain line and ensures your clogged drain line gets cleaned the right way every time!