WI 2920-B EZ Mag Wheel Insert is a (black colored) factory stock wheel style insert that is precision molded for a secure, snug pressure fit. Designed to fit inside any 1/2" (.500") inner diameter wheel, EZ Mag Wheel Inserts are guaranteed to give your project an amazingly realistic appearance! Designed to work with 1/24 and 1/25 scale slot cars and scale models.