Our Sun Knees are proven to deliver UPF 50 protection even when the fabric is stretched by 30%, the lightweight material used for these slip-on knee covers will keep you covered and cool so you can lay down the hammer at the height of summer. DETAILS: Pedal to Zero(TM): Going by bike 7mi / 11km offsets the climate impact of this garment In-R-Cool(R) technology to provide optimal skin-cooling effect and moisture management when you perspire ELITE Transfer fabric with UPF 50+ sun protection and Ice-fil(R) Easy slip-on fit BioViz(R) reflective elements for low-light visibility