This commercial grade Spin-Loc connector is use to connect the 3/4" drip tubing to a main lateral tee with 3/4" female pipe thread. To use this Spin-Loc fitting, push the drip tubing over the barb with the "O" ring and thread the sleeve over the drip tubing to secure. The tight seal for the Spin-Loc fittings is ensured by the rubber "O" ring on the barb, which provides a quality water-tight connection.