Slime Balls 60mm, 78a Screaming Slime Light Ups with transparent green urethane, yellow LED bulbs, and black core. Slime 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. 60mm x 40.4mm, 78A.