Ben 10 was one of the very first series Isaac got into. For his birthday I found the just released and extremely cool Ben 19 with plumber suit action figure. This is part of the new series, Ben 10 Ultimate Alien.
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 "armour".