The Select Series Knitted Sun Shade combines Coolaroo"s unique knitted fabric with a smooth operating roller clutch system. The knitted fabric blocks up to 90-percent of damaging UV rays, yet is breathable and allows hot air to escape and cool breezes in, saving up to 40-percent on cooling costs. The weather resistant fabric and components resist fading, mold, and mildew, ensuring your shades will look great for a long time, no matter the weather they are up against. Cooloaroo"s light filtering knit reduces glare without darkening a room"s interior. Stainless steel tie downs keep this sun shade firmly in place.