This special adapter is designed for connecting 3/16" brake tubing to your metric brake caliper or master cylinder.
One end has a female port that accepts a 3/8-24 SAE inverted flare (concave seat) tube nut. The other end has male 10x1.0mm fine threads with an unthreaded lead tip and a metric bubble flare (convex seat). This requires an M10 port with a concave flare seat.
High-pressure brass construction is rated to 2000 psi (136 Bar). Sold individually.
Note that the male side is designed to seat at the flare. It is too long to use with a crush washer.