These are specially made for Lambretta upgrades in the U.K. from top quality gasket material, with far superior sealing qualities. Specifically used for fuel and oil under pressure unlike standard gaskets.
These are 1.0mm, twice as thick as the standard 0.5mm type, these can help if you have clearance issues between the mag housing and crank. 1mm gaskets are available by request, these are more expensive
The gasket material is made from aramid and man-made mineral fibres bonded with nitrile rubber. Suitable for sealing out oils and fuels, also water, steam, gases and many chemicals!
Complies with test requirements of BS7531 Grade Y