Compression straight coupling in 15mm x 15mm size chrome plated. Straight coupler compression plumbing fitting 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. Manufactured in the UK for use in all plumbing and heating works.