John Guest Speedfit Superseal Pipe Insert 22mm (Pack Of 50)Always use a JG Speedfit superseal pipe insert when connecting Speedfit pipe to a Speedfit push fit fitting. Inserts play a vital role in providing extra support to pipework, ensuring that the ends of the pipe are kept nice and round, and minimising any loss of shape that can occur when cutting. JG Speedfit superseal pipe insert contains dual o rings to provide even greater sealing security than a standard insert. The first o ring is on the stem that