Brass Material Size: 1/16" Barb to #10-32 Male Thread. Fits: 1/16" ID tubing. Included in Barb Kit (RPI Part #ADK080) & Control Block Kit (Major) (RPI Part #ADK241) Fits: Control Block 300 & 500 series, Foot Control Signal Relay Main Body Valve, and Water Coolant Relay Assembly (A-dec Part #38.1810.00)