Trap-Vent is for use on a lavatory, water cooler or sinks that do not receive a discharge from any appliance. Trap-Vent is rated up to 6 DFUs on a horizontal wet vent. The Trap-Vent cannot be installed on kitchen sinks, laundry tubs, or a sink that receives discharge from any kind of appliance. Do not use where pumps or pressurized flushing devices are used. Please follow all instructions carefully during installation.