The base of the lid and washer has a bottom base of 70mm. The lid is completely handmade. I personally polish it, drill it and polish it.Can be installed on a motorcycle tank. To confirm my words, look at my photos in this lot. If you have any questions about the installation, write to me. I try to send as soon as possible. It is possible to make an individual cover according to your sketches. The item "Custom Arc Gas tank caps cover Harley Davidson, Bobber, Chopper, Triumph" is in sale since Tuesday, October 27, 2020. This item is in the category "eBay Motors\Parts & Accessories\Motorcycle Parts\Body & Frame\Gas Tanks". The seller is "garage_nishtyaki" and is located in Energodar. This item can be shipped worldwide.