Cosmetic only - requires Arsenal Overhaul (i will add a vanilla one if this becomes popular) although it is easily modified in the character_desc_general.xml file if you do not have it. Gives most low-ranking soldiers Berill suits with the gas mask (icon is changed as well), this does include some lieutenants (who appear with berets), although stalkers with berets and without the masks are less common now.. The soldiers being ill-equipped was a gripe with the USS faction, I can understand not being prepared training-wise, but I think they would be well-prepared equipment-wise, even down to the private. Gives them a more uniform look as well.