PW50 Aftermarket Minis Oil Tank Spacers are used when you put on an upgraded tapered steering bearing kit on your bike as the tapered steering bearings are a taller over all height than the stock ball bearings, so when you are putting the tapered steering bearings you will end up have a little bit looser fitting oil tank and if you want to get the tank fitting snug again these spacers will take up the space allowing it to fit tight.