This ia a amazing Coin! 2 Pieces USN SPAWAR San Diego NIWC Naval Information Warfare Systems Command / Naval Information Warfare Centers. Huge Chargebook List of MCPONs CPO Navy Chief Challenge Coin #753W. The chargebook opened measures approx. 4 1/2″ x 3 1/2″ inches and 1/4 thick. The insert measures approx. 2 3/4 x 1 3/4 inches. 3 1/2″ x 2 3/8″ inches. PLASTIC COIN STAND NOT INCLUDED. Please add any additional items to your cart.