features a padded sleeve designed to fit a compatible hydration system(Not Included), bottom essentials pocket with a storage net to hold helmets, dual hipbelt small pouch to accommodate your phone, players, keys, etc.. With such versatility in usage and durability in raw material, it is a wonderful backpack for your short-term hiking, climbing, trekking, or any other adventurous activities. Features: RIPSTOP AND WATER REPELLENT: Made of anti-tear polyester fabric(lining), rip stop and water repellent, to ensure long-lasting performance. VENTILATED BACK SYSTEM: Cooling back panel with mesh shoulder straps constructed with breathable synthetic material for comfort. STORAGE COMPARTMENTS: One main compartment with a padded sleeve to fit a compatible hydration system; A bottom essentials(helmet holder)pouch; Two small pouches on the hipbelt panel to accommodate phones, MP3 players, keys, small items, etc. FRONT, BACK REFLECTORS: Several reflectors on the back and front of the bag to improve the safety at night cycling. CONVENIENT TO OPERATE: High-tenacity zippers with pullers for convenient opening or closure and longtime use. Note: Others except items listed in the package list are ONLY for reference.