The BELL GOSSETT hot water circulating pump is a 1-phase model that is thermally protected. The 3-pc., oil-lubricated booster features a flexible spring-design coupler that permits quiet operation. Sleeve bearings constantly circulate oil over bearing surfaces. Mechanical seal. Close centrifugal impeller/body tolerances minimize water slippage. Bronze housing. Potable Circulating Pump, 1/6HP This product contains a chemical that is regulated under California Proposition 65. Warning This product contains a chemical known to the State of California to cause cancer. Warning This product contains a chemical known to the State of California to cause birth defects or other reproductive harm.