Primaplus compression fittings are premium brass fittings manufactured in Britain to EN 1254 standard and are WRAS approved. These fittings are suitable for a variety of installations, including water and gas. The kite mark approval signifies adherence to the highest British standards. IMPORTANT SIZING NOTE - Most plumbing products are measured using BSP thread dimensions which measure 1/4 inch larger than that stated, therefore this 1/2 Inch BSP thread actually measures 3/4 Inch in diameter. If your thread measures 1/2 Inch in diameter then you require the 1/4 Inch version of this product. This listing is for a Pack of 1. Using a 1/2 inch BSP (please see sizing note) male thread, this will join a 15mm chrome plated plumbing pipe in a 90 degree elbow arrangement. The seal is formed with the olive and not the thread, so PTFE is not recommended as it can reduce the compression capabilities of the thread.