Casio G-Shock MUDMASTER Carbon Core Mud-Resistant Outdoors Mens Watch GGB100-1A9This is a model from the G Shock Mudmaster Series, designed for use in extreme environments scattered with rubble, dirt and debris, and uses carbon materials. The use of high rigidity carbon on the case keeps damage and deformation at bay, and ensures a high level of airtightness and shock resistance. This model also features a construction that protects against the invasion of mud, a stainless steel panel back, and a back cover made of shock