The Mag-Tank takes a new twist on top tube bags. Instead of a zippered opening, access to the bag is by contoured top flap held in place by a magnetic buckle with mechanical engagement. It will not unintentionally open and spill your gear. Hook and loop straps hold the bag securely to the stem and top tube. - One-hand access while riding - Side panels stiffened with HDPE plastic sheets - Wrap around panel design is padded with closed cell foam - Adjustable height daisy chain front attachment with foam spacer block - Please note - while the cover to this bag is designed to shed rain and spray, due to the large panel opening it is not a sealed bag or water-proof - VX21 and 42 XPac - 420 Denier yellow and red lining - Closed cell foam padded tube sections - HDPE sheets