This is the BBE Clan's German Special Forces mod, It adds in five skins that involve Germany's Military and Special Forces such as Military Police, and KSK Officers. This mod can be used in Single Player and Multiplayer. This mod wasn't made by me, And I don't claim credit for it either, This was originally on the swat3reunited.com website. Reuploaded to get interest in Swat 3 again.
Put the file inside the Swat 3 file under mods and enable via the Swat 3 mod launcher and you'll have it working.