A puck, when used in ice hockey, is a hard black disk of vulcanized rubber. A standard puck is one inch thick (25.4 mm), three inches in diameter (76.2 mm) and weighs between 5.5 and 6 ounces (156-170 g). Pucks are often marked with team or league logos on one or both faces. But there are more than one type of puck. The one mentioned above is a standard puck which is the one usually used but there are lighter pucks and heavier pucks that are used. (wikipedia)