Great for residential foam insulation spraying! Graco's Reactor A-20 is a lightweight, easy-to-use air-driven unit that combines Gusmer's proven reliability with Graco's advanced technology, including digital controls and improved heat control. For more advanced proportioning options, see the Reactor H and E series proportioners. * Great for entry-level roofing, construction and other field-related spraying jobs * Compact design is portable, easy-to-move, and uses less floor space