Kotap 40-ft x 40-ft Heavy-Duty 12 by 12 Cross Weave 8-mil White Poly Tarp, Item: TRW-4040 FINISHED SIZE: 38-Feet 6-Inch by 39-Feet 4-Inch More durable and longer-lasting than regular spec and competing tarps: 12 by 12 Weave (8-mil thick) vs. 10 by 8 or 10 by 10 or 12 by 10 Strong Grommet Applications: Grommets spaced every 18-Inch and reinforced plastic corner bars All edges heat-sealed and reinforced with polyethylene rope Rot and Shrink Proof