Plumbing fittings and methods of manufacturing plumbing fittings for use in drain-waste-vent systems are described herein. The plumbing fittings include a housing having at least one receiving member defining a cylindrical bore for receiving a piping member therein, at least one annular seal fittingly inserted in a receiving member, and an annular locking member dimensioned for receiving the piping member therethrough. The annular locking member includes teeth extending inwardly for locking the piping member within the receiving member. The plumbing fittings also include an annular releasing member inserted within the receiving member and movable between a locking position and a releasing position whereat the beveled portion of the annular releasing member presses against the teeth for releasing the piping member.