Jabsco INlet Non-Return Valve- 3/4" I.D. A check valve give quicker and easier flushing response on many manual and 37010-Series electic toilet installations For use with manual and electric toilets using sea water flush.; Simply fit in inlet suction hose, near seacock but just above waterline.; Prevents loss of prime in above waterline installations.; Retains water in bowl of 37010-Series electric toilets installed above waterline; Fitting: Connections for 3/4" I.D. Hose.; Size: 4-1/2"L X 2-1/8"W X 2"H;