Topeak Bag Backloader Seatpost MountFeatures Easily mount to saddle rails & Seatpost with hook & loop straps Roll top closure The included waterproof inner bag keeps contents dry and easy access Built in air release button keeps waterproof inner bag compact Features a light clip for extra safety Minimum Clearance : H > 9 cm 3. 5 Specification Capacity 10 L 610 ci 15L 915 ci Attachment Hook and loop fastener Waterproof Yes Closing mechanism Roll Top Material Polyethylene nylon