This is the beta combine elite soldier (and before people say "but that's the beta sniper!!!!" no it isn't. It might have been used as the sniper at some point but the original model is called combine_elite.mdl)
You can choose to replace the regular Soldier, the Prisonguard or the Elite Soldier with it (or everything). Additionally you have the choice between 4 differently styled skins. It also has optional custom sounds made by Forstbite.
Ey mate, that is a pretty neat skin. I'm so glad this was finally done!
Also, just to let ya know, those sounds were made by a user known as Frostbite (Link to his steam profile since he doesn't have a Gamebanana account: http://steamcommunity.com/profiles/76561197975832672/ ). Could you please put him in the credits list?
On that note, the sound files are modified sounds of the soldiers from 1187, a Half-Life 2 mod made by TeamGT, you may want to credit them for the original sounds as well.