... of tower crane in stock 2. High quality tower crane spare parts Detailed Product Description1. Topkit tower crane : Jib lenght (30- ... -speed winding motor and "Shengjian " brand, the quality is the same with exporting supplier "Potain " .( 5 ) Luffing mechanism is double- ... .8 grade).Our company are specialized in tower crane and spare parts, we could supply Potain, SCM, Yongmao, Shenyang, and Jianglu, ...