G-Shock Watch Heavy Duty GA-900A-1A9ER. The heavy duty models that are great for wear in tough environments and as street fashion items as well. The GA900A 1A9 model comes with a yellow resin band. The industrial design of these models is created by a 10 sided bezel that resembles the shape of a nut. The bezel is secured by four screws for a tough and rugged look. Combination timekeeping is provided by analog hands along with a digital display for the ultimate in operational ease. The design of the hands and the graphic figures that appear in the digital readouts create a powerful face design that enhances readability. The band connection and all buttons have checkered surfaces that prevent slipping and contribute to operational efficiency.