This special adapter fitting lets you connect your 1/4" brake tubing to a 1/8 NPT female port. It is designed for installing a proportioning valve or line lock in an existing hard line, but it is also great for connecting a hard brake line to an aftermarket caliper with 1/8 NPT threads (such as Wilwood).
The male end of this adapter has 1/8 NPT male tapered pipe threads to fit a standard 1/8 NPT port. The female end accepts a standard 7/16-24 inverted flare tube nut (not included). To install, just apply a thread sealant (sold separately) to the NPT threads and screw the fitting into your port. Then screw your tube nut into the adapter. Sold individually.