These Y4 asymmetric Ywheels feature an advanced design that is conical on the outside, and square on the inside to help lock into grinds. The base of the wheel is also bigger which is ideal for wider decks/trucks. They have a durometer of 65D and is the hardest wheels that Yellowood makes. This means that it will have the optimized amount of grip and slide! Dual bearings are used so that there is more contact with the axle making the fitment much more tight/stable to prevent wobbles and jamming.