ultra sonic welded seams are 40% exclusive! • tyvek® top panel is triple-stitched to the polypropylene side panels • polypropylene side panels breathe to help prevent mold and mildew • contemporary two-tone design • water resistant tyvek this product uses dupont™ tyvek® material ultra-shield rv cover's top material is made by laminating two layers of spun-bond polypropylene to a third outer layer of dupont™ tyvek® water resistant breathable • blocks damaging uv rays • superior all-weather performance • tough yet breathable travel trailer what is ultrasonic welding? ultrasonic welding is a method of joining two materials by converting electrical materials being held together under pressure to create the weld item# length members reg sale 34t to 37 this product can expose you to chemicals california to cause cancer and birth defects warranty • covered air vents help prevent trapped moisture • zipper entry doors for easy access • front and rear cinching straps reduce loose fabric for a perfect fit • tyvek® top protects roof against uv and moisture universal-fit cover measuring instructions finding the right size cover is easy! simply measure your rv from end to end at the longest do not use the rv model number or manufacturer-stated length as actual length may vary do not include propane tanks or hitches do not include rooftop accessories such as air conditioners or satellite antennas ttttt गगगगगगगगगगगगर maintain your rv