The Charter Arms The Walker revolver is designed specifically for carrying about when on a walk, but you still want to be prepared for whatever varmints might come your way. It features a DAO hammer, full rubber combat grips and a matte finish. Black nitride is a process that adds hardness to the finish of the revolver. It also reduces friction and wear. With a scratch-resistant surface and extended life in the rifling and chambers, Black nitride keeps your Charter handgun looking - and working - like new!