The Roadmaster M Challenger 18 houses our COSC certified manufacture caliber with an 80-hour power reserve, while the Roadmaster Challenger 18 is a day/date model that runs on the RR1102 movement and the Roadmaster Challenger 18 TMT features our mechanical thermometer module. It is outfitted with micro gas lights and a gas tube inset on the aluminum rotating bezel. Inspired by mechanical engineering and human courage. Limited to 1,000 pieces each. Case size is 40mm