MASTERCOOL (57161 Black Aluminum R410A, R22, R404A 2-Way Manifold Set with 3-1/8" Gauges, 3-60" Hoses and Standard 1/4" Fittings Solid aluminum design Free-floating piston type valves reduce o-ring wear Extra access port for vacuum line Silicone dampened, 3 1/8" gauges smooth out needle movement Extra large sight glass for visual refrigerant check