MK5 Manual Black Waste Sanitation Pump. Whale has led the way in manual diaphragm pumps for the marine world for decades.. The Mk 5 sanitation is a reliable fully housed black waste pump - reliability when you need it most. Features and Benefits. Can be mounted in various orientations/positions. Tough plastic housing keeps in nasty smells. Large virtually unblockable valves. Easy to clean (no tools required). High performance- 56 ltrs (14.8 US gals) per minute. Wide hose connections for maximum performance - 38 mm (1+"). Lightweight design for easy operation. WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.