Because the lifting handling products are very expensive , but the working frequency of crane system is not so high , we generally suggest that the clients can adopts the main –auxiliary hook model . The main hook can be used to lift the electricity generator unit , and the auxiliary hook can be used to make maintenance and replace the spare parts . As the equipment needs assembly, so they has a higher accuracy requirements about the crane system .we generally use absolute encoder to improve the lifting accuracy. It can only meet the use of equipment functions, but also reduce the cost for customers. Based on different needs of customers and different situation on-site , we can also tailor the right proper equipment .