Always use a Speedfit pipe insert when using Speedfit pipe. Two types of pipe inserts are available: Standard and Superseal. The Superseal insert contains two 'o' rings to provide even greater sealing security. Both types of inserts are suitable for JG Speedfit hot and cold water and heating systems. Note: inserts must be used on all Speedfit connections. Designed, manufactured and assembled in the UK by John Guest Speedfit.