The LightBloc ZIP™ incorporates the Draper LightBloc style headbox design, and 1-3/4" wide side channels (1" smaller than our standard Manual and Motorized LightBloc). The side channel incorporates a "zip" detail that is welded to the vertical sides of the fabric. This "zip" feature" prevents the fabric from coming out of the side channels. The channels can be face or jamb mounted. The bottom sill channel is 3/4""L" angle. UL Listed as a complete unit. Available with fabrics from U.S.-based weavers Phifer and Mermet USA.