BLACKMAX Refrigerant Manifold Set: 2 Valves, 3 Hoses, Series Blackmax, 3 1/8 in Gauge.

Analog manifolds connect to HVAC systems and allow users to measure the system pressures using the integrated rotary dial gauge. They diagnose system issues and add or remove refrigerant from the HVAC system. Analog manifolds do not require batteries but are less accurate than digital manifolds.