Mark T Cox is wearing Arctic Clothing. His L1A1 SLR is equipped with a SUIT 4x optical sight. Often issued 1-2 per section. Note improvised muzzle cover, possibly Argentinian. The rifle as standard would have had a leather cold weather muzzle cover, fitted to the bayonet lug. The idea with the leather one was that if you forgot to remove it, you could shoot it off!