6x13x5 Flanged Ceramic Revolution bearing (F686-RSZC) by Avid Racing Concepts is a high-quality steel/chrome bearing with ceramic balls (Si3N4) and our Revolution seal. Check your manual for the correct size for your vehicle if you are not certain.
The Revolution Series bearings are a low friction bearing with several options to help satisfy anyone's desire. What makes this bearing unique is that it has a rubber seal on one side while having a metal shield on the other. Rubber seals are great protectors against dirt but at the price of a little more friction due to the tighter seal. Now the performance of a metal shield is excellent but allows dirt to get in easily. So with the Revolution series, you run the rubber side towards the outside and the metal towards the inside. You get the protection of the rubber but the added performance by having one less rubber seal. But you don't have to stop there, if you are truly performance-oriented and want the least amount of friction then you're in luck. You can quickly pop off the rubber seal with an Xacto and place the metal shield facing outward in your hubs. This is the best performance you could attain while maintaining some protection from dirt.
This bearing is greased which will offer you the most protection and longest life available due to the extra layer of protection grease provides. This means your bearing will not spin freely when they are brand new like an older bearing does. You will have to run the bearing a few times so that the grease will move to the sides of the bearing to offer you that extra level of protection barrier to dust entering while also freeing the bearing up.