Danfoss / Eaton Weatherhead 10005B-102

For low pressure shop or service air lines, this fitting is a common match. It is also often used on low pressure lube and oil lines, so it fits that same light duty service type work.

The threaded end is 1/8 inch NPTF, which stands for National Pipe Taper Fuel. That thread form is built to create a pressure-tight mechanical seal on its own through metal-to-metal contact, so you get a more reliable connection than standard NPT without depending entirely on tape or sealant.