I ordered these bearings to replace the ones on my treadmill motor. They have been professionally packaged in a plastic front (room for each bearing) with a cardboard cover. Others have complained about having to wipe off the packaging wax or grease, but I haven't had that. They are pre-lubricated but the grease is inside the bearing and both sides are sealed. They don't appear to be the fastest bearings in the world (meaning if I hold the center and spin on the outside they don't spin for very long), but in my case the motor spins. They definitely fixed the engine screeching noise and I now have spares to replace this one if it ever fails. It was a lot cheaper than buying a new motor or treadmill.