When selecting a Zoomlion crane, you must prioritize lifting capacity (tonnage) and boom length to ensure they meet your project requirements. Key technical factors include the engine type (e.g., Weichai or Cummins) for fuel efficiency, the hydraulic system stability, and the load moment indicator (LMI) accuracy. For crawler cranes, evaluate the ground pressure and track durability, while for truck cranes, focus on the chassis strength and axle configuration to ensure road legality and stability during operation.