Fits on passenger seat (with or without sissy bar) or luggage rack. 10" (25,4cm) in diameter x 18" (45,7cm) in height (when fully expanded); 23 litres; 1200 denier UV-rated weather-resistant textile material with removable rain cover; Sissy bar strap that attaches quickly; external bungee storage; carry handle and detachable shoulder strap; Roll-top closure with high-strength hook and loop for adaptable storage and water resistance; Adjustable fasteners; Quick-access zippered pockets on the sides; Heavy-duty welded D-Rings and a full mounting strap kit are included for bikes that don't have sissy bars.