Really hard-to-find Polish Wz.50 combat helmet. These were highly influenced by two different designs: The Soviet SSh-40(shape) and the Italian M33 (Liner). These are one of the better-made Eastern-Bloc helmets that are available.
These have been used all over the world, notably by the Syrian Military in the 6 Days War, and the Iraqi military in the Iran-Iraq War.
Actual helmet is pictured. Great shape.