Made by A.G.Parker & Co. Ltd (Later Parker-Hale Ltd), the Model 5A aperture backsight for the No.1 S.M.L.E. rifle A sight with integral fixing plate. A new model with removeable windarm, the 5A sight was made originally about 1925 and continued in production for many years - until the outbreak of the World War 2 and after.
This sight is without the Iris