The ports on the Jabsco 45490-1000 "Y" Valve are replaceable. The original valve is supplied with three 1-1/2" (38 mm) ports, and an extra 1" (25 mm) straight inlet port for connection to macerating toilets. This kit includes all four ports. It does not contain the O-rings that seal the ports. (The O-rings come in the 45488-0000 Service Kit.)