2012 Heavy duty type double ball bearing swivel caster wheel KHX2-H4 *Dia.100-150mm *cap.250- ... 50mm H4 Heavy duty type double ball bearing swivel caster wheel Heavy Duty Caster /Four Size available (4'',5'',6'',8 ... bearing, 5.8mm thickness pressed steel .4.Top plate swivel brake type ,fixed type ,threaded stem type,Bolt hole type ... Display] H4 Heavy duty type double ball bearing swivel caster wheel