The bestselling skate bearing brand in the USA, Bones REDS are manufactured to Bones Skate Rated specifications in a manufacturing facility dedicated to producing the highest quality skate bearings possible. They are thoroughly inspected before being shipped, and offer an outstanding combination of performance, durability, and low cost. Features Single, non-contact, removable rubber shield for easy cleaning and less friction High speed nylon ball retainer for greater strength and speed Pre-lubricated with Speed Cream racing lubricant Skate Rated clearances, tolerances, materials, and lubricant ------------------ Adding Kata Skateboarding Samurai Speed Ring Bearing Shim Spacers in between your bearings will align the bearing to the inner hub of your wheel. This will effectively reduce friction and movement inside the hub of the bearing. With Samurai spacers installed, the energy between turns is absorbed by the wheel and not the bearing itself, reducing impact and side load on the be bearing itself. Reducing stress on your bearing components will help prevent your bearings from exploding or seizing up while riding your board. In addition to stress reduction, adding spacers will hold your wheels steady on your trucks during slides, preventing that annoying and sometimes dangerous choppiness experienced when sliding square-lipped wheels. Ultimately, you will have a bearing that will endure the demands of a downhill racer or freerider. If you are doing any Racing, Downhill, Freeride, and especially Slides and hard carves, you will want to add Samurai Spacers to your board. One pack is enough for 4 wheels