HKB-FZH (copper based), HKB-FZL (aluminum based), and HKB-FZP (resin based) steel balls are held in place, with copper alloy, hard aluminum alloy, and POM resin as the matrix, respectively. On their outer circular surfaces, holes are machined in an orderly arrangement, appropriate size, and special shape, into which rolling bearing steel balls are inserted. The mouth adopts the latest groove circular locking ball technology, effectively solving the problem of traditional locking balls and indentation locking balls not completely preventing steel balls from falling off. A 90 ° stopper is machined at the bottom of the hole to allow the steel ball to rotate freely inside the hole without falling off. Due to the diameter of the steel ball being larger than the wall thickness of the retaining ring, the steel ball is higher than the inner and outer circular surfaces of the retaining ring during use, directly contacting the matching hole and shaft, causing the base (retaining ring) to float in the middle, and the difference between the radius of the matching hole and the shaft is smaller than the diameter of the steel ball, that is, the steel ball is in an interference fit with it, with high fitting accuracy and flexible relative movement between the shaft and the hole. It is a product that keeps the circle updated and upgraded.