079783030 - SOLD EACH... 2 of these sit on your frame to hold the gas tank up. They fit many bevel drive twins where there is a rubber Oring or a tank bungee on the back holding it to the frame. Usually found on 900SS etc. Sold each, as one might come up missing sometime. The ID is actually 25mm as measured and since it is rubber, it can easily sit on your 28mm or 32mm diameter bevel drive frame tube.