The RONLAP WORKBENCHCASTERS UPGRADED 4 Heavy Duty Retractable Casters by SPACEKEEPER are designed for heavy-duty material handling tasks. With a weight capacity of 660lbs per caster, these retractable casters offer smooth and easy mobility for workbenches, tables, or other equipment. The durable construction and retractable design make them a reliable and space-saving solution for a variety of industrial applications.