WI-2913-S (Silver) EZ Mag Wheel Insert is a classic "Baby Moon" style wheel cover that is precision molded for a secure, snug pressure fit. Designed to fit inside any 5/8" (.625") inner diameter wheel, EZ Mag Wheel Inserts are guaranteed to give your project an amazingly lifelike / realistic appearance! Designed to work with both 1/24 and 1/25 scale slot cars, and scale models.