Eva,Nylon KEEPS KNEES SAFE & COMFY: Our gel construction knee pads are designed to provide your knees with the extra protection they need to keep them safe. Using a heavy-duty thick poly shield, our work knee pads prot ect your knees from cuts and scrapes so that you can work comfortably for longer! HEAVY DUTY CONSTRUCTION: By using Heavy-weight nylon thread, we bring you foam soft EVA knee pads that can withstand years of use while being breathable enough to prevent sweat build-up to keep your knees cool and dry for optimal performance. FOR ALL YOUR NEEDS: Thanks to the soft gel core and EVA foam padding you can use our professional construction knee pads for countless hours making these pads suitable for indoor and outdoor work like Wood Flooring, Gardening, Carpentry, Welding, Roofing,.