The Speedfit Collect Locking Clip 15mm with model number #CM1815-B has a push-fit design for easy installation. It is made of pex material and is suitable for central heating systems. This is compatible for connecting copper pipes.It has been manufactured and kitemarked to British Standards - BS7291: Part 3: Class S. It is lead-free, non-toxic and corrosion free. It is lightweight and flexible.The Speedfit Collect Locking Clip 15mm has a push-fit design for easy installation. It is made of pex material and is suitable for central heating systems. This is compatible for connecting copper pipes.