- This is the Large dished Washer that was used on the bottom of All Norton International petrol tanks to hold the rubber Washer that protected the tank from vibration. Four were Fitted per petrol tank. the same Washers were also used on All pushrod and sidevalve tanks. - This washer was also used on Bolt-Thru Manx petrol and oil tanks on the top fitting and the bolt-thru rubbers I sell in this section fit within this washer - These items are just as per the original item, except manufactured in stainless steel. They look beautiful polished, with the stainless dome nuts on Manx Bolt-Thru tanks - Price is per each