No. 9 Mk I Bayonet (Socket Knife blade type), 1953, Serial # 316149. It for the for the No.4 Mk.I and No.4 Mk.II Lee Enfield Rifles. The British No 9 bayonet was introduced in 1947 and combined the Bowie blade of the No. 5 and No. 7 with a steel socket, and was manufactured until 1949. It was mainly issued to the Royal Navy. The block is marked with an arrow, the symbol of the British war department. No scabbard. Total length: 26 cm; length of blade: 20 cm. This bayonet was the last type made for the Lee Enfield No. 4 Mk.1 rifle.