Adapts from 1/2 in CPVC to 1/2 in male metal pipe thread and features lugs for fastening. Used on tub and shower faucets to adapt from 1/2 in CPVC riser to shower arm. Sometimes called a drop ear elbow. Hand tighten only, seals by means of a special elastomeric gasket to ensure leak-proof seal, use of joint compound or Teflon tape is neither necessary or recommended.