The canopy replacement tarp with valance overhang is made for 10" x 20" frames and is fabricated using 6 Oz, 12 mil. polyethylene materials and contains grommets every 18" on the underside of the cover. Every tarp is Waterproof, Mildew proof, Rot proof and UV Resistant. Canopy replacement tarps with valance feature an 8 inch overhang around the frame edge and contain pull ties at the four corners, which tighten the cover for a secure fit. For 10" x 20" frames. Actual tarp size delivered is 12" x 20" (11"5" x 19"6" finished). The two extra feet is needed to cover the high center angle. Each Rafter Length Must be 6" In Length For This Cover To Fit.Please See The Diagram In The Images