These brake lines are 3/16" with 10mm metric fittings which will work with your Datsun metric fittings. These lines will connect to your master cylinder, wheel cylinders and existing brake line fittings with M10 inverted flare fittings. Available any many lengths and can be connected together with the "coupler" fitting to achieve almost any custom length. Sold individually by length. These lines are a dark gray color.