... .Accept gas 2.Synchronized 3.3.5mmTHK mechanism,chair mechanism,pull back mechanism,swivel chair mechanism,chair parts Item.no.NBC003Material THK ... /ctnG.W:15.73kg/ctnUsageOffice swivel chair,mesh chair, pull and back chairCertificateBIFMA TUV SGS testPacking4 PCS/CTNCtn Size:56*26*32cm20 ...