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) 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