UNIVERSAL ONE-SIZE FITS ALL STAINLESS STEEL HURRICANE WINDOW CLIP mounts to any thickness PLYWOOD boarding to the exterior BRICK window casings for quick hurricane and storm protection. EASY TO INSTALL- NEVER LOSE CLIPS AGAIN PERMANENT INSTALL typically use 4 per window. Then push the plywood board into the window frame and it is securely held in place, using exactly the same original wedge-grip principle. NO special tools, caulking, adhesives or glue required. Easy to install and remove by one person. DESIGNED FOR USE DURING WIND STORMS - These Clips are made of heavy duty 316 Stainless Steel .040" thick (Competitors are 0.030" spring steel). They ensure a super tough hold during the strongest windstorms. There is less chatter and deflection of the plywood due to these super strong clips. REUSABLE - HURR-PRO window clips are hard-wearing, rugged, rust-proof Stainless Steel and will last year after year. They can be reused over and over and are not affected by Plywood swell or thickness variations over time. Once installed, you never have to worry about them again. 100% GUARANTEE! Protect your home from high winds, storms and hurricanes. We guarantee this product to be defect free and provide an unconditional money back guarantee if you are not 100% SATISFIED.