Adfors Extra-strength screen is our strongest fiberglass screen. The extra-strength screen's heavy-weight weave is 40% stronger than standard fiberglass mesh providing greater protection and offering excellent outward visibility. As a premium screen product, extra-strength screen is tested using ASTM 3656 standards. Adfors is also leading the industry by making our full line of fiberglass screen ortho-phthalate-free, ahead of industry standards.