Amazon.com: Metalwork 304 Stainless Steel Metric Compression Tube Fitting 8mm OD x 1/4" NPT Male Adapter Coupler (2 Pcs) : Industrial & Scientific
World Wide Fittings MALE METRIC ORB by MALE PIPE STAINLESS STEEL 3249XM18X08SS | Zoro
Stainless Steel Compression Thread Type Inch and Metric Tube Fittings and Adapters - China Hydraulic Fittings and Adapters, Swagelok Connector | Made-in-China.com
Pipe Fittings 304 Stainless Steel M5 M6 M8 M10 M14 M20 Metric Male Thread to 4mm 6mm 8mm Quick Pipe Fitting Union Connector Fit PU PTFE Tube -(Size: 4x2.5mm; Thread Specification: M5):