Fiberglass staves are sewn in the panel. Seal is formed along the sides and top of the truck when the vertical and top panels are pushed inward by the truck. Supporting structure is made of 2 x 4 wolmanized lumber. Shelter is protected by safety yellow steel guide protectors. The top header piece measures 132"W and contains a drop curtain which measures 36"H. Two vertical pieces measure 126" tall with vertical flaps measuring 21"W. When installed the shelter will close door opening down to 90"W x 90"H opening (between flaps). Additional features include bottom corner draft pads, steel guide protectors and vertical guide strips on vertical flaps. All dock seals and shelters on this page are not returnable.