Brass 15mm compression x 3/8 inch BSP female iron straight adaptor fitting.
Compression plumbing fittings do not require heat or solder. The joint is formed by tightening a nut and compressing the olive (included with fitting) onto a copper or plastic pipe, which forms the seal. They can be used on wet pipework, and are suitable for hot and cold systems.
** BSP thread sizes are measured a special way - have a look at our information page for more details **