For Hose Size: 1-1/4″ Freshwater flushing of your inboard is as simple as connecting a garden hose. Clear polycarbonate with stainless steel spring. Transparent body allows for visual inspection of water flow. Durable check valve system activated by water pressure from a garden hose. Check valve automatically shuts off hull intake whenwater pressure is applied. Can be used with onboard generaters. Kit includes: FlushPro valve with two clamps, hose fittings & clamps, 7′ of hose, and Fig. 499 water inlet fitting.