Specification: Material: Brass Hex size: 12mm Thickness: 8/10/15/20mm Net Weight: 8mm?27g 10mm?43g 15mm?60g 20mm?79g Package List: 4CS * Wheel Hex Hub Adapter+ Notice: 1. The products in the package are shown in the picture, only the 10mm,15mm and 20mm Adapters have washers and spacers. 2. The Adapter is suitable for TRX4 and TRX6; but TRX6 car needs 6 Adapters, it is recommended to buy 2 packs for TRX6 car.