Adding a (12mm) width extension per side of the vehicle for a wider, more stable, stance. 12mm Wheel Hub Extensions add 12mm to the track width of your Axial SCX10 Rc4wd Wraith D90, and Wraith Crawler etc Top-Quality Materials & Superb Craftsmanship Precision anodized, Aluminum material, lightweight and durable Lightweight upgrade instantly enhances overall performance in handling and durability. Extensions fit over axles and secure to axles with included screw pins. Wheel is secured with long aluminum wheel nut. Material: Aluminum Alloy Total length: 15mm Hex size: 12mm Screw Head Diameter: Approx. 8mm Pin: 2*10mm Color: Black Fit for: 1/10 RC Rc Crawler Scx10 Rc4wd Wraith D90 etc. Make sure your 4 wheels use a 12mm hub already Suitable for hub aperture 7mm, the nut with a 5mm Suitable for screwing on a 4mm axle screw The hex adapter has a 6mm hole in it Suitable for the hole in the axle is 2mm (if no hole these wont be suitable) 8 x RC Hex Hub Extension Adapter 8 x Nail 8 x Pin