Suttner ST-2750 Pressure Wash Guns with Extension 500 Bar 30 Lpm. The Suttner ST-2750 wash guns are the highest pressure rated wash guns available in a standard body size. These 500 bar rated guns are made from stainless steel with impact resistant plastic casings. All ST-2750 guns also come with Suttner’s LTF trigger technology, which means that the trigger is 40% easier to pull and 90% easier to hold when in operation, compared to standard wash guns