Designing features of PWA Series Pneumatic ActuatoExtruded aluminum ASTM 6005 body with both internal and external corrosion protection having honed cylinder surface for longer life and low coefficient of friction. Dual piston rack and pinion designforcompact construction, symmetric mounting position, high-cycle life and fast operation, reverse otation can be accomplished in thefield by simply inverting the pistons Multiple bearings and guides on racks and pistons, low friction, high cycle life andprevent shaft blowout. Modular preloaded spring cartridge design, with coated spring for simple versatile range, greater safely and corrosion resistance, onger cycle life. Fully machined teeth on piston and pinion for accurate low backlash rack and pinion engagement, maximum efficiency. Stainless steel fasteners for long term corrosion resistance Full conformance to thelatest specifications: ISO5211, DIN 3337 and Namur or product interchangeability and easy mounting of solenoids, limit switchesand other accessories.