Size - Size: 6.4mm ( 1/4 Inch ); Nail Head Diameter: 7mm / 0.28"; Thread Size: 5.3mm / 0.21"; Total Length: 12mm / 0.47"; Thread Pitch:32G. Material - Made of carbon steel, prevent rust and corroding, has high hardness and is strong and wear-resistant. Lightweight, only 0.47g, helps improve your running speed and can achieve better results in competition. Feature - Tapered needle shape track spikes can increase the friction between the shoe and the ground, prevent skidding and ensure safety. It also improves the balance of traction, flexibility and speed as you run. And will not damage the runway. Application - Provides optimal grip for dry terrain such as athletic fields. General size for most running shoes to use, suitable for 100-400m sprints. If you like running, cross country, or you are a sports enthusiast, these track spikes will be of great help. Package Content - 5pcs x track spikes.If you have any questions, please feel free to contact us.