This Sunbelt Sink Trap is Waterless - No Need For Trap Primer. Specifications•Type: Straight Valve•Inlet Attachment: Slip Joint•Inlet Size: 1-1/4 Inch•Outlet Attachment: Slip Joint•Outlet Size: 1-1/2 Inch•Color: White•With Mounting Hardware: No Designed To Close The Waste Connection Below A Sanitary Fixture To Prevent The Escape Of Foul Sewer Air Into The Dwelling Unlike Conventional Waste Traps, Does Not Rely On Trapped Water To Create A Seal Provides Enhanced Plumbing Design & System Efficiency, Without Compromising Performance Or Risking The Escape Of Foul Air Into The Living Space From The Drain Or Sewer | Sunbelt Waterless Sink Trap, 1-1/4 Inch In-Line Adaptor