lost Sentry Safe combination. First, find your safe’s Serial Number. The Serial Number is printed on the small label on the right side of safe ( on paper tag near hinge) or under handle. just note your model # and the serial#. Please check out selecting 1 set combination and then enter your sentry safe model # and serial #s in the additional information / comments section on the check out page. We will email you the next day with the sentry safe lost combination and the opening instructions.