60mm Frog Trips Light Ups OG Slime Red Glitter 78a Slime Balls Skateboard WheelsSlime Balls Light Ups wheels feature LED lights that light up when you roll, powered by the rotation of the special wheel spacer and wheel core. No batteries required. Light Ups come with removable replaceable Bronson Speed Co. G2 bearings. Slimeballs OG Slime shape is a versatile, symmetrical center bearing cruiser wheel with soft, 78a urethane. *Special spacers are required & axle nuts may need to be tightened fully for proper light ups operation.