With ACER Racing’s National and World Champion reputation in the high performance ball bearing industry we set out to engineer the best ceramic skate bearing at any price. First we started with our tried and tested Ceramic Nitride Pro Series silicon nitride balls (Si3N4). The same super hard balls that gave us the reputation as ‘the hardest balls in the industry.’ These balls are matched for consistent concentricity per set. They are polished using diamonds for a super smooth and shiny finish. Their durability is unmatched by any other ball or material in the industry. With a melting temperature of 2552 degrees F and the best modulus of elasticity in the world, these are the best balls period. We use our special synthetic and American ACER Racing SIN oil lubrication in our ceramic skate bearings which has an extremely wide service temperature range of from -50 to +120 degrees Celsius with an incredible speed factor of 1 million. We integrate our HSR inner ball bearing cage for durability and strength with superior heat resistance at high RPMs. This insures that your ceramic skate bearings will spin faster, longer. We seal our ACER SK8 ceramic skate bearings with two no contact grey seals which will resist the elements while allowing simple removal for easy cleaning when necessary. Each seal is embossed with our trademark ‘ACER RACING CERAMIC’ logo to insure that you are receiving the original ACER SK8 ceramic skate ball bearings. These are the best ceramic skate bearings at any price. Whether used in your skateboard, inline skates, longboard, roller skates, fidget spinners or anywhere a size 608 8x22x7mm ball bearing is used, rest assured you will be running the finest ball bearings in the industry. These have become the #1 bearing for use in fidget spinners and will spin longer, smoother and faster than any other fidget spinner bearing.