Using these Alta CONTOUR 360 knee protectors is easy. First, adjust the dual strapping system to fit your knees comfortably. Make sure the non - slip rubber strip on the back inside holds the pads in place. Then, you're ready to get to work. When using them, avoid sharp objects that might damage the VIBRAM caps or the Cordura Nylon cover. After work, clean the knee pads with a damp cloth to remove dirt and debris. Let them dry naturally. If the pads get wet, dry them thoroughly before storing. Keep them in a cool, dry place to maintain their quality. These knee protectors are adjustable to fit most sizes, but if you find it hard to adjust, check the AltaLOK Easy On/Off locks and the Alta STRAP - keeper System for a better fit.