Aluminum Line Nut

-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