The waterproof bike briefcase with roll closure can be mounted on the right or left side of the rack it can be quickly mounted and easily taken off the rack single handed the office bag offers room for two large a4 files 40size l41 office supplies mobile etc with the padded notebook sleeve 40available as extra accessory41 it is a perfect laptop bag 40up to 15441 two large 3m scotchlite reflectors and a reflective ortlieb logo ensure safety in the dark and in bad weather c