MasterCool 98661-PRO is a versatile manifold gauge set designed to assist you in servicing and maintaining automotive air conditioning systems that use R12 or R134a refrigerant. It enables you to accurately measure and monitor system pressure, diagnose potential issues, and add or remove refrigerant as needed. The manifold features dual gauges, color-coded hoses, and a variety of fittings to ensure compatibility with different A/C system configurations.