... above, and this kind of material is made of rubber plastic and has blister in plastic. This hardness gauge ... 93, JJG304-2003.Parameter:Type A: applicable to general rubber, synthetic rubber, vulcanized rubber, soft rubber, leather, wax, etc. Type C: applicable to ... .Type D: applicable to hard rubber, hard resin, acrylic, glass, cushiony plastic cement, printing plates, fiber, etc. Parameter: Item No. ...