Professional Instruments 8523 Air Bearing Spindle Tested Spins Smoothly HProfessional Instruments 8523 Air Bearing Spindle Tested Spins Smoothly H The large black body of the bearing in the middle is the fixed section, the rest of the assembly on both sides rotates, see video for example. Good used condition, Unit has been aired up and spins perfectly smooth, no motor included, comes as pictured. Bearing will be taped very well to prevent movement during shipping, moving without air supplied can damage the air bearings.