1-1/4" Or 1-1/2", In Line Sump Pump Check Valve, Prevents Water Backflow Into Sump Basin, Corrosion Resistant Construction, Includes 2 Rubber Reducing Sleeves & 4 Stainless Steel Clamps, Ready To Install On 1-1/2" Discharge Pipe, Reverse Reducer Sleeves For Use On 1-1/4" Discharge Pipe, For SSE Use Only.