An improved lockable container, which is configured to resist being pried open or being otherwise successfully attacked within predetermined time and tool set limits. An exhaust device in which a second exhaust muffler at a rear portion of an exhaust system extends rearwardly from an engine is disposed in a rear portion of a rear cowl wherein a rear end surface of the second exhaust muffler is covered with a resin-made muffler rear cover. Doping concentration in the central section is lower than that of the circumferential region.