Scaffolding caster, double ball bearing, an advanced design,eliminating kingpin. 2 brake pedals ... caster have excellent performance in construction circumstance.Scaffolding caster, double ball bearing, an advanced design,eliminating kingpin. 2 brake pedals for ... -field certification.Different spec. of pulg stem including ball spring structure.Double Precision ball bearing;Wheel: 98°A Strong PU on PP. ...