The MacWrap collar is made up of two layers. The bottom layer (next to the pipe) is made of a tough, woven polypropylene fabric with a thick rubberized mastic coating with a peelable protective paper that is removed when the collar is applied to the pipe. The outer layer consists of an impervious polyethylene with a rubberized mastic that is bonded to the bottom layer. Between these layers are steel straps sheathed in tubes that allow the straps to slip freely and tighten around the pipe.

The ends of the two layers are off-set so that in applying to the pipe the bottom layer overlaps itself. The straps are secured and the top layer then covers the exposed portion of strap, completing the joint. The collar comes complete, ready for application.