Capacity up to 300 pounds per caster. These institutional casters are ideal for any light duty application where the caster must be totally immobile when the caster brake is applied. Caster Model K3A has a unique brake which locks both the wheel and the swivel bearing at the same time. This “Total-Lock” brake insures that the swivel caster will not turn when the wheel is locked. This combination wheel brake and swivel lock is essential for safety in some applications – such as on worktables, tablesaws, and medical equipment. The Total-Lock brake is desireable whenever a brake is needed because it makes a swivel caster totally immobile. The wheels featured with Caster Model K3A are non-marking, and all except Polyolefin can be used on hardwood floors. Polyolefin wheels are best at reducing the risk of a flat spot occuring when loads are left standing for prolong periods. Gray Soft Rubber and Polyurethane wheels have a sealed precision ball bearing. They provide floor and cargo protection, quiet operation, and are very easy rolling. Try a set of 4 casters. You will be amazed at their performance!