The Anaquda RS ball bearing set contains four high-quality Anaquda ball bearings ABEC 9 and two aluminium pacers. These bearings come from one of the best ball bearing factories and offer a perfect support for the spacers with the wide inner ring. The RS cover protects against moisture better than standard covers. The RS cover can be carefully removed for maintenance purposes. Note: High quality steel was used. However, this is not rustproof. Under extreme conditions, despite the RS cover, water can enter the inside of the ball bearings. ABEC9 RS cover 4 ball bearings including 2 spacers spacer width: 10.3 mm