This is a package of Air Line Retainer Fittings from Robart. FEATURES: Knurled for tool free hand tightening. Aluminum construction. Threaded through entire body. INCLUDES: Six air line retainer fittings. REQUIRES: Assembly on air tubuing and retract fittings. SPECS: Height: 6.0mm (.238") Outside diameter: 6.4mm (.252") Inside diameter: 4.0mm (.159") COMMENTS: Air line fitting retainers connect your air tubing to your fittings. The tubing goes to the fitting, and the retainter holds it in place by threading over the tubing and the fitting. pjm 4/20/02 ir/kh