Description AC Manifold Gauge Set This Manifold Gauge Set is designed to test automotive air conditioning systems using R134A refrigerant only by comparing the high and low pressure readings using the vehicle A/C system specifications. This Set can be used to test evacuate and fill automotive air conditioning systems Colour coding on gauges valves and hoses to ensure correct installation LOW - Blue Gauge - 0-220psi . Blue Hose - 1/4in. FFL x 50in. HIGH - Red Gauge - 0-500psi. Red Hose - 1/4in. FFL x 50in. Yellow Hose - 1/2in. ACME x 50in. Large 70mm gauges with impact-resistant lenses. Gauge Accuracy + / -2 percent Sight glass for viewing condition of refrigerant. Quick-connect fittings. High pressure safety valve.