2012 Heavy duty type double ball bearing swivel caster wheel KHX2-H4 *Dia.100-150mm ... at 50mm H4 Heavy duty type double ball bearing swivel caster wheel Heavy Duty Caster /Four Size available ... new latch technical.blue zinc plated, Top plate swivel housing ,with Precision double ball bearing, 5.8mm ... thickness pressed steel .4.Top plate swivel brake type ,fixed type ,threaded stem type,Bolt ...