Reactor A-25 Bare ProportionerReactor A 25 Bare Proportioner The Reactor A 25 is a Graco engineered spray foam proportioner that gives you the reliability you expect on the jobsite. It maintains consistent temperature control, even when you're spraying at maximum flow rates resulting in better quality foam. Ideal for the following spray foam applications: Residential insulation Technical Specs Maximum Working Pressure 2000 psi Maximum Hose Length 210 ft Maximum Fluid Temperature