Design: The Pangong Pannier bags are designed to fit most rectangular pannier rails/saddle stays. The goal was to maintain compact dimensions so that the bags don't stick out too wide. The Pangong bags hold shape even when empty. Specs: 20L+20L capacity (Each bag expandable by 5 liters) 38 cm X 28 cm X 15 cm (+5cm expandable) 1 primary compartment with roll top waterproof liner2 external side pockets Compatibility: Fits most motorcycles with rectangular saddle stays(Exhaust placement and aftermarket parts will have to be considered before buying, make sure the bag doesn't touch any hot parts or exhaust gases)  Mounting: Hook-Strap based mounting with the option of choosing strap position from amongst several optional loops mounted on the bag Features: Waterproof main compartmentRetains Shape when empty Kit Includes: 2 sets of mounting straps (each set has 3 straps)External cover