This is special edition bundle with Basicase ™ Android Apps license key included for more fun!. SpecificationsBrand: HOBBYHOT Bearing Material: Chrome Steel Ball Material: Chrome Steel Recommend for Model: MUGEN RC MTX-3 Bearing Model, Dimensions & Quantity: 686-2RS (Outer Diameter: 13mm / Internal Diameter: 6mm / Width: 5mm) x 10pcs 6700-2RS (Outer Diameter: 15mm / Internal Diameter: 10mm / Width: 4mm) x 6pcs 6701-2RS (Outer Diameter: 18mm / Internal Diameter: 12mm / Width: 4mm) x 2pcs Please note that the information above is provided by the producer of the replacing bearing. All the recommended models are for reference only. Buyers should confirm the correct size and quantity of the bearings for your own model before purchased the replacing bearings. Basicase™ and HobbyHot™ are registered trademarks. Products only distributed by authorized seller.