A system and method are provided to provide enhanced exception messages for exceptions thrown by virtual machines. The focus detection apparatus includes an optical system, which divides a luminous flux from an image-taking optical system to form a first pair of optical images having an interval between them in a first direction and a second pair of optical images having an interval between them in a second direction, and a photoelectrical conversion device. A second wider seat support is at least partially detachably arranged between the waist belt and a region of the front piece at a level corresponding to the waist belt. A hollow extension bar may be connected to the lug wrench to apply additional leverage.