If you have a Fill point adaptor ( french, Acme, UK, Spanish ) to use with your UK fill point and the rubber O ring has become damaged then this is the 21.8mm replacement rubber 'O' ring you need.
It simply goes over the male threaded bottom section of your adaptor and seals against your UK fillpoint
For full information on how this GAS IT part works and functions plus how to install it, please visit the GAS IT Online Knowledgebase and search for the part number or product description.

Any sales questions please do not hesitate to email or call our GAS IT Sales on sales@gasit.co.uk or Telephone 01286 832443