The HOLDRITE® Acoustical Standard Clamp™ #255 is a strong, sound rated variable closure clamp that installs as a standard two hole pipe clamp with one or two screws. Two acoustical inserts insolate the pipe from the support structure, reducing piping noise and vibration, while allowing normal pipe expansion and contraction. The clamp has a grip strong enough to serve as a stub-out clamp. Clamp supports up to 1" CTS tubing sizes. Supports Copper, PEX, CPVC pipe, conduit, etc. Frame work complies with UL94V-2 fire rating and UPC listed.