This is a package of four 4mm Serrated Wheel Lock Nuts from Pro-Line. FEATURES: Fits any RC car or truck that uses 4mm axles Aluminum construction, anodized blue in color Serrations dig into wheel to prevent loosening Inner nylon lock ring YOU WILL RECEIVE: Four 4mm Serrated Wheel Lock Nuts in Blue SPECIFICATIONS: Hex Size: 7mm Inner Diameter: 4mm jxs 12/13/12 ir/jxs &