4sets in stock for 4000-5000meters drilling rig API standard NOV materical good ... SY/T5527. The sheave and bearing are interchangeable for those of mated crown blockModelYC225Max. hook load2250 ( ... chinese NOV ,our prodcts : rotary table ,hook, travelling block,crown block,swivel ( same as Chinese NOV company ) ,our ... to work with us ~! YC225,travelling block for drilling rig,tiger brand,in stock