The Plumbers' Uniforms are specific outfits that the Plumbers wear during missions. They are based on nanotechnology and can have multiple gadgets attached to them. They serve many purposes, from space suits to simple "armor". They're even capable of supporting one's life underwater, especially under heavy water pressure. Kevin has also modified his, Gwen's, and Ben's Plumber suits where they are able to deliver electric shocks whenever they are unable to use their powers meanwhile inside the suit.
Some Plumber suits are modified for those outside their native environment for certain species and required life support.