Description:Suitable for all surfaces: tartan, asphalt, dirt, grass, cross country, ice, etc.Recommended for all track and field disciplines.Made from high quality heat-tested steel for maximum durability.4 different styles available: pyramid, needle, tartan and Xmas tree. The screw diameter is 5mm. The total lengths range from 12-18mm.Specification:Material: SteelNeedle: diameter: 5mm, screw length: 5mm, spike length: 13mm, weight: 26g (12pcs weight)Tartan: diameter: 5mm, screw length: 5mm, spike length: 8mm, weight: 23g (12pcs weight)Pyramid: diameter: 5mm, screw length: 5mm, spike length: 7mm, weight: 20g (12pcs weight)Xmas Tree: diameter: 5mm, screw length: 5mm, spike length: 8mm, weight: 24g (12pcs weight)Package Includes:12 Pieces Steel Shoe Spikes(6 Pack)Note:Please allow 0-3mm error due to manual measurement.