100% polyurethane. Its particularities : Detachable elasticated mesh helmet holder; TSA combination fastening system; side pocket with an anti-theft cable ; an inner pocket with RFID protection ; a quick-access zipped side pocket, two zipped pockets on the straps, two tie straps ; two side pockets ; one charging pocket on the side with a USB and a micro USB port (cable included ;an inner compartment for a laptop up to 15” and padded storage for a tablet to 11” ; two inner zipped pockets in knit mesh ; two inner pockets including one for bottles and another for a powerbank ; two detachable zip pouches for cables and accessories ; reinforcements on the back, padded adjustable straps and an adjustable chest strap.