This hose adapter can be used to attach a vacuum hose or pool cleaner to a threaded port. Backwashing your pool filter is essential for keeping your water clear so this hose adapter is necessary.Details:White4" x 1.75"Heavy duty plasticRecommended for use with a stainless steel hose clampFeatures a stepped smooth opposite end that fits 1.25" and 1.5" hosesMale threads fits 1.5" femaleFor outdoor use