The 52mm Ryan Sheckler Prospec Wheels are made different that traditional urethane. The riding surface is missing the "grooves" you see in most wheels. It's also not completely smooth or slick like other wheels. These Prospec wheels are grounded down, giving a more of a textured feel. There is no break in time, and they are made to slaughter any and all terrain. Basically they give flatspots the boot. No hype, no BS, just the real deal. Never settle, demand Plan B quality.