Specifically for the Component B side of Graco Reactor E-XP2, E-XP1, A-20, and R2 E-30 systems. The 245971 is a 0.552 sq/in, Side "B" displacement pump used in Graco Reactor electric proportioners like the E-XP2 and A-25 systems. Designed for 41cc displacement, it handles pressures up to 3500 psi.