➤IconCasterWheels 6 inch Steel Wheels Casters comes in a 4-pack , which includes 2 Top Brake Lock Swivel Caster and 2 Swivel Top Plate Caster. ➤These Non-Marking wheels make it easier to move heavy loads on smooth, hard surfaces. ➤Each casters has a load capacity of a 1200 lb. (4,800 per Pack) - 4 Per pack. ➤These casters are durable and are able to withstand extreme temperatures, lowest -40°F to 500°F. ➤The caster swivels 360-degrees and attaches easily with a 1-7/8 in. x 2-9/16 in. plate and 4 screws. ➤➤The locking system features a Top Lock Brake, that is made up of completely sealed ball bearings for smooth swiveling and the best protection against dust and debris. ➤Swivel casters have completely sealed ball bearings for smooth swiveling and the best protection against dust and debris. ➤The kingpin less swivel raceway distributes impact better than standard kingpin casters, enabling smooth swiveling and extending service life. ➤The axle nut for these casters are 1/2" diameter, with Double ball bearings with hardened raceway for extra strength. ➤The Top Plate Overall Size is: 4" x 4-1/2" | Bolt Hole Spacing: 2-5/8" x 3-5/8" slotted to 3" x 3" | Attaching Bolt Size: 3/8"