SS Flex with Quick-Fit Adaptor Push-Fit systems are gaining popularity in fulfilling many requirements of the Plumbing and Heating Industry. These fittings will withstand temperatures and pressures well in excess of normal working conditions when installed to confirm with Good Plumbing Practices. How Quick-Fit Fittings work: These fittings have a unique grip-and-seal construction made up of a collet with stainless steel teeth to grip the pipe and an O-ring to provide a permanent leak proof seal. The additional benefit of the twist-and-lock fitting is that a twist of a screwcap locks the pipe in position and gives increased compression on the O-ring, for even greater security. High quality systems with just a twist! The John Guest SpeedFit Fitting is a registered trademark of John Guest International Limited and the system is approved by the British Board of Agrément and the Water Regulations Advisory Scheme. Speedfit 'PEM' fittings and PEX Barrier Pipe are Kitemarked to BS7291 Parts 1 and 3 Class S Licence No KM39767. It is also accepted by British Gas Service for service contracts and approved by BBA, WRAS, KIWA etc.