Aluminum line nut. Made from durable billet alum. and anodized for corrosion protection. RBS carries blue, black and super nickel for the racer that wants options for fitting colors.
-3 = 3/16" tube
-4 = 1/4" tube
-5 = 5/16" tube
-6 = 3/8" tube
-8 = 1/2" tube
-10 = 5/8" tube
-12 = 3/4" tube
-16 = 1.00" tube
-20 = 1.250" tube