Our toolbox caster sets are designed with the end user in mind. We know how important it is for keeping your equipment rolling safely and easily, whether on the job or at home in the garage. The 4" by 4-1/2" top plate with slotted bolt holes accommodates virtually all major models of toolboxes and gang boxes (including Knaack, Greenlee, Jobox, Husky, and many more, please check your measurements to ensure compatibility.) We offer several wheel types so the toolbox or tool chest casters perform optimally on any surface. Wheels with maintenance free ball bearings are available as a higher performance option. The standard toolbox wheels have a roller bearing maintained by zerk grease fitting in most instances.