The MR33 bearings are low friction bearings which help to satisfy racers desire. These bearings have been tested by multiple world champion Marc Rheinard also during several ETS races. The performance of the MR33 bearing-sets are awesome and allows to decrease everyone´s lap time. What makes this bearings unique is that it has a rubber seal on one side while having a metal shield on the other. Also these bearings are hand selected and filled up with a special high performance oil. If you are truly performance oriented and want the least amount of friction then you can get it. You can quickly pop off the rubber seal and place the metal shield facing outward in your solid axle, gear diff, central-and front/rear transmission. Of course you have less protection, but the best performance ever.