The fuel caps GW0602 and GW0602-1 are among our most unique products. These models fit a wide range of vehicles such as automobiles, motorcycles and agricultural tractors. The outer shell is treated with chrome plating, while the inner shell in zinc plating. The main difference between GW0602 and GW0602-1 is that one is vented and the other is non-vented. Some people purchase these two models as sets.