1) Spherical function, two rows of spherical rollers, a common groove on outer ring, two grooves on inner ring that tilts in an angle to the bearing center. 2) Works when the axle distorted orassembled. 3) Bearing size can changed, thespherical range: 1?- 2. 5? 4) Can bear bigger load, not only theradical load but also two directionradical load with better anti-shock abilities. 5) Main types: 21300 series, 22200 series, 22300 series, 22300 series.