Thank you for viewing. This is a set of 17mm aluminum bearing rollers with plastic rings for Mini 4WD, dyed black. *520 bearings are not included. *If you wish to have 520 bearings installed, please comment and they will be sold for an additional 330 yen. *These are handmade by an individual, so 100% accuracy cannot be guaranteed. Please consider purchasing with this in mind. *Returns regarding the quality of the product are not accepted, so please be aware of this.