Built to last. Heavy duty quality. Extra large carrying capacity with added back support and special waterproof wet kit compartment to keep files and books clean. Reflective features for safety.Standard - 17" (h) x 13" (w) x 6.5" (d) - 23 LitresXL - 19.5" (H) x 14.5" (W) x 7" (d) - 31 Litres