This is a 10-pack of Atrek Steel 4mm Flanged Serrated Wheel Nuts in a black finish. These are high-quality nuts suitable for any 1/10 scale RC vehicle that uses a 4mm wheel axle. The flanged base helps to distribute pressure evenly on the wheel, while the serrated underside bites into the wheel surface to prevent it from loosening during use. This pack is a workshop essential for any RC enthusiast, perfect for replacing lost or worn wheel nuts or for completing a new build.