Swagelok Style compression fittings to suit 1/4 or 3/8 stainless or aluminum hardline 

Available Size 

1/8 npt x 1/4 hardline

1/4 npt x 1/4 hardline

1/4 npt x 3/8 hardline

3/8 npt x 3/8 hardline

x1 Fitting