This LTWFITTING Compression tube fitting is made of brass for durable. And it connects to tubing on one end and has an NPT male connector on the
LTWFITTING 1/4 in. O.D. x 1/8 in. MIP Brass Compression 90-Degree
LTWFITTING 5/8 in. O.D. Comp x 1/2 in. MIP Brass Compression
LTWFITTING 5/8 in. O.D. Comp x 1/2 in. MIP Brass Compression
Everbilt 5/8 in. OD Compression x 1/2 in. MIP Brass Adapter
LTWFITTING Brass 7/8-Inch OD x 1/2-Inch Male NPT
LTWFITTING 5/8 in. O.D. Comp x 1/2 in. FIP Brass Compression Adapter Fitting (20-Pack) HF6610820 - The Home Depot
LTWFITTING 5/8 in. Brass Compression Insert Fitting (50-Pack) HF63PT1050 - The Home Depot
LTWFITTING Brass 1/8-Inch OD x 1/8-Inch Male NPT
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LTWFITTING Brass 1/4 OD x 1/8 Male NPT Compression Connector Fitting(Pack of 5) : Industrial & Scientific
LTWFITTING 5/16 in. O.D. Comp x 1/8 in. MIP Brass Compression Adapter Fitting (25-Pack) HF685225 - The Home Depot
LTWFITTING 5/8 in. O.D. Comp x 3/4 in. MIP Brass Compression Adapter Fitting (5-Pack) HF68101205 - The Home Depot