... industry standard SY/T5527. The sheave and bearing are interchangeable for those of mated crown blockModelYC225Max. hook load2250 (500000)kN ... as chinese NOV ,our prodcts : rotary table ,hook, travelling block,crown block,swivel ( same as Chinese NOV company ) ,our mud pump ... hand , please give tiger a chance to work with you !welcome stronger sales engineer to work with us ~! YC225,travelling block for ...