Fernco 3001-150 3001-150 Proflex 1-1/2 in. Neoprene Shielded Coupling

It is the 1-1/2 inch size in the Proflex line. Sizing here is by the pipe outside diameter the sleeve is molded for, so a 1-1/2 inch coupling goes on 1-1/2 inch pipe ends, and stepping to a different pipe size means a different part number, not a different clamp setting.

The Fernco 3001-150 Proflex is a 1-1/2 inch flexible pipe coupling with a neoprene sleeve and an outer shield. It joins two pipe ends of 1-1/2 inch size in a drain, waste or vent run, so you can tie into existing pipe without solvent welding or threading. The shield is what separates it from a plain unshielded rubber coupling: the band carries the joint and keeps the sleeve from ballooning under load.

Neoprene is the standard sleeve material for drain, waste and vent work and is what the Proflex uses. A shielded coupling like the 3001-150 is the right call where you are joining dissimilar pipe materials or repairing a cut-in and you need the joint to take some load. A plain unshielded rubber coupling is for lower-demand, accessible repairs; if your inspector is calling for a specific listing on a hubless joint, confirm that listing against what your local code requires before you commit to any coupling.

The coupling ships as an assembly, sleeve and shield together with its bands, so you are not sourcing clamps separately. What you do need on the job is a torque driver or nut runner set to the band torque, and clean, square-cut pipe ends on both sides. Out-of-round or burred ends are the usual reason a flexible coupling weeps.