These little Spacers may not look like much but are great in terms of improving how a board rides and prolonging the life of skateboard bearings. The 10mm bearing spacer sits between bearings inside skateboard wheels, and over the truck axle they ensure riders never over-tighten their bearings and inadvertently crush them. They also ensure that bearings are running completely parallel to one another which will reduce wear. If you're spending big money on premium bearings it's worth buying 4 of these to help you get the most out of them and aid you in building a secure, reliable set-up. These are supplied in a simple jiffy bag. Price is for ONE spacer.