Making elaborate miniature models of tourbillons, gearboxes, engineering machinery and bionic toys only to find that the strength, stiffness, tolerance and smoothness of the printed shaft system are not up to expectations? This Precision Shaft System Kit contains multiple sizes of miniature deep groove ball bearings, thrust ball bearings, bronze bushings and pins, which help to solve the strength and accuracy problems in designing the shaft system and linear motion of small-sized models. Take your miniature model to the next level.