These are the O-rings that go on the bottom of  the Zenith Stromberg carburetors. They are used on many British cars including Jaguar, MG, Triumph and many others. Easy to change out.  This listing is for a set of 4. I do combine shipping for multiple items. Click "Buy it Now" and request shipping amount if buying more than one item from my store and I will send an invoice.  Shipping is for the lower 48 USA. If elsewhere, please write for shipping costs.