This Cartridge Series twist pen is made of a Winchester 308 Cartridge with Curly Maple on top with a Gold finish. This pen has designed for the US Navy Chief Fan in mind. This pen is created using a real 308 casing and 30 caliber bullet that is modified to accept the refill. The cartridge is not coated and will show patina but can be cleaned if desired. This product uses a standard cross style refill obtainable at any office supply store.