600D Nylon material. ■ Two side compartments for water bottle storage. ■ Large central compartment as well as a small compartment with organizer, both with YKK-zippers. ■ MP3 player compartment with headphone cord port. ■ Bungee helmet securing system. ■ Waist belt for extra stability. ■ LED tail light mounting strap. ■ Padded back with open air flow channels. ■