Machined from hi-strength aluminum alloy, this 2"-diameter, anodized cylinder is drilled and tapped to accept O-ring sealed scuba valves (3/4-14 NPS). The bottom has a 1/4" FNPT air inlet port and two 1/4-20 bolt holes for mounting it to any bench top. Used to test repaired valves or, with an installed valve, makes a great bench top workstation for fixing/testing regulators!