What comes with the assembly rack with a bonus, if the load is applied, the turning of the caster becomes very bad. This product is very smooth because it uses bearings in the swivel portion. If the wheel is made of rubber, it will deform in the long term. The urethane winding is used comfortably without deformation or vibration.
Part of the caster chair used at the store was damaged, and it was replaced and repaired by oneself. Quality is "excellent". I asked for a spanner at the time of replacement, but my misunderstanding did not match the thickness and purchased a very thin spanner of 4 mm thickness from another company. If you need additional casters, I'd like to request it here by all means.