PACKAGE: You will receive 12pcs starting block spikes, enough quantity for the replacement of old or broken spikes. DURABLE: Track starting block spikes cleats are made of steel material, weather resistant, and durable for long time use. DIMENSIONS: The replacement sprinter pedals cleats thread is M4.8 and they are compatible for all standard domestic starting block and are easy to use and replace. FEATURE: The stable design can offer grip and stability during use, great for track and field equipment such as starting block and running aids, offering GREAT GIFT: The replacement studs are easy to use and quick to install. The running block studs are good gifts for your family, friends, colleagues, and other people who love sports. Specification: Material: Steel Size Chart:Thread diameter 0.48cm/0.19inch Nail tip length 1.12cm/0.44inch Package Includes: 12 Starting Block Spikes(2 Pack) Note: Please allow slightly errors due to manual measurement and different monitors.