Oust Bearings - MOC 5 Street &ndash; Skateboard, Longboard, Cruiser, Inline Unique bearing design, unlike popular brands, allows for tighter tolerances High strength carbon steel ball cage ideal for street skateboarding Oil hole in the shields for easier cleaning and applying oil. (Recommend Oust Metol Oil) High Rockwell material hardness, and high surface polish for increased speed, performance, durability, and low friction. Doubled sided non-removable metal shields for superior protection, unlike single sided bearings