ABS sanitary tee for tying a horizontal fixture branch into a vertical drain or vent stack — the workhorse junction behind a sink, tub, or lavatory where a branch line meets the stack. The branch inlet enters with a curved sanitary sweep that turns flow downward into the stack, so waste keeps moving and solids don't catch at the joint the way they would on a square vent-tee inlet. All three ends are hub sockets sized for Schedule 40 IPS ABS, solvent-welded for a rigid, sealed joint. It meets ASTM D2661 and CSA B181.1 and carries cUPC and NSF/ANSI 14 certification, the listings an inspector checks on a residential or light-commercial rough-in across the GTA. Stocked in 1½" and 2" — the sizes that cover most fixture and branch tie-ins. Sanitary tees are non-pressurized DWV only; test hydrostatically, never with compressed air or gas.