This is a specially made Lambretta base gasket with the correct stud spacings for the 200/225 block lambretta engine casing. These have been checked to make sure they are correct. Big surface area around ports for porting. Essential you get the correct base and head gaskets for setting correct port timings and squish height.
These are available in 0.5mm, 1.0mm, 1.5mm and 2.0mm
2.5mm and 3mm available here: http://www.lambrettaupgrades.co.uk/apps/ webstore/products/show/7680638
Price includes VAT @ 20%