The select series knitted sun shade combines Colorado unique knitted fabric with a smooth operating Roller clutch system. The knitted fabric blocks to 90% of damaging UV rays, yet is breathable & allows hot air to escape & cool breezes in, saving up to 40% on cooling costs. The weather resistant fabric & components resist fading, , & , ensuring your shades will look great for a long time, No matter the weather they are up against. Colorado's light filtering knit reduces glare without darkening a room's interior. Stainless steel tie downs keep this sun shade firmly in place.