AN MFS SUPPLY EXCLUSIVE: These 4’ (4 pack) bracing bars are sized for the Secureview 3’x 4’ sheets and are able to ship via UPS as well. Both specialty sized products are applicable towards MFS Supply’s $450 free shipping threshold, and available for purchase online. The bracing system works by utilizing interior clamping beams that are composed of high density polyethylene. The beams are 1 inch in thickness and secured using corrosion resistant carriage bolts and/or security head screws.