YELLOW JACKET, long recognized as the industry leader in HVAC&R service tools, is the first to offer a set of large 3-1/8-in. red and blue dry manifold gauges specifically calibrated for monitoring R-417A, R-422A and R-422D refrigerant alternatives. These 1% accuracy (Class 1) gauges with a front recalibrating screw are available individually or on the YELLOW JACKET TITAN™ 4-Valve Test and Charging Manifold. or 800/769-8370. — Ritchie Engineering Company, Inc, YELLOW JACKET® Products Division.