Nelson Composite Sheet (CPS™) is a rigid, elastomeric, fire resistant panel used to seal penetrations and maintain the rating of fire rated floors or walls. It consists of a rigid panel, primarily composed of a 5/16” thick elastomeric sheet, bonded to a 28 gauge galvanized steel sheet on one side. The composite sheet is reinforced with hexagonal shaped steel wire mesh and bonded with .003″ aluminum foil on the back side.