... ; 2-High strength and hardness, compound hub; 3-100x24mm. Alloy core scooter wheels:1-CNC machined alloy 6061 /T6, High strength ... and hardness, compound hub.2-The high quality metal core wheel fits almost all scooters. Such as Razor, Madd gear ... any time,we will reply you asap.Thank you! Alloy core scooter wheels