Brass Nut Frost Flare:

Designed for copper tubing.  Fittings are sized by the copper tube outside diameter.

Tyree #: 111259 - 1/4" Flare, 41FP-4
Tyree #: 111359 - 5/16" Flare, 41FP-5
Tyree #: 111459 - 3/8" Flare, 40-6
Tyree #: 111659 - 1/2" Flare, 40-8
Tyree #: 11165A - 1/2" Flare x 3/8", 38-8-6
Tyree #: 11175A - 5/8" Flare x 1/2", 41FP-108
Tyree #: 11175B - 5/8" Flare x 3/8", 41FP-106
Tyree #: 111759 - 5/8" Flare, 40-10
Tyree #: 111859 - 3/4" Flare, 41FP-12