Dometic/Sealand’s “TW” series pumps offer a unique bellows pump that can run dry without damage and pass solids up to ½” without clogging, making it more versatile than impeller-type pumps. This unit is self-priming up to 10 feet and can process 300 gallons per hour. The “T” Series Discharge Pump 12V is energy efficient, drawing just 6 amps at 12 volts. “T” and “TW” discharge pumps are used to empty holding tanks or other tanks such as grey water or fish boxes. These pumps are NOT to be used as substitutes for vacuum pumps.