When selecting the sling size, the size, weight, shape of the hoisted load, and the hoisting method to be used must be included in the calculation. The ultimate working force is required to work simultaneously. The type of environment and load must be considered. The slings of the proper length must be selected to have sufficient capacity and to meet the usage. If multiple slings are used simultaneously to lift the load, the same type of sling must be used; the material of the flat sling cannot be affected by the environment or Load impact. Regardless of whether the attachment or soft lifting lugs are required, careful consideration must be given to the end of the sling and the auxiliary accessories and lifting equipment.