This new MUDMASTER model was created especially for this whose work takes it into areas where piles of rubble, dirt, and debris are present.A special vibration-resistant construction lets them stand up to wear while operating cutters, crushers, drills and other heavy machinery to clear way large obstacles. This is CASIO's first analog watch to come with Mud Resist construction, which helps to ensure that nothing gets into the watch when down and dirty work takes you deep into the dirt and sludge. Multiple gaskets are used on the pipes that guide buttons and shafts, which keeps mud out. These pipes not only act to protect buttons from impact, they also enhance button operation. The screw-in force of the screw lock bezel on an internal gasket further increases mud resistance.A new bezel structure lets you visually check whether the bezel has been screwed in adequately.