... 2. Oprional ABS and automatic slack adjuster available Liangshan Darong Traffic Mechinery co.,ltd. is a professional manufacturer of semi-trailer ... well as semi-trailer BPW/American axle assembly,axle tube, the single point suspension ,tandem pendel axle series,spoke axle series,outboard ... major varieties of our RSC brand, including axle, BPW/American axle assembly, the single point suspension systems, ...