SGS 37MM Caster-3704 SERIE ANSI/BIFMA X 5.1 Certificate 50MM Caster-5007 SERIES ANSI/BIFMA X 5.1 Certificate 60MM Caster-6001 SERIES ANSI/BIFMA X 5.1 Certificate 65MM Caster-6504 SERIES ANSI/ BIFMA X 5.11 Certificate 65MM Caster-6506 SERIES ANSI/ BIFMA X 5.11 Certificate 75MM Caster-7506 SERIES ANSI/ BIFMA X 5.11 Certificate Patents Taiwan Patent – M527716 Hollow casters for furniture Taiwan Patent – M540759 Caster hub structure Taiwan Patent – M579596 Silent pin for office chair Taiwan Patent – M320499 Furniture casters German Patent –Silent pin for office chair