When you purchase a scissor lifts directly from manufacturer or through agency, there are certain features that have to be considered.
Load Capacity: The maximum capacity of the load that has to be handled by the lift has to be known. All the models are not designed to handle huge loads so purchase the one which is appropriate for your use.
Height: Similar to the load capacity, each model can be raised to a particular limit. If you have to handle with lifting the loads to various floors then purchase one that can handle a higher extension if not get according to the required height extension.
Purpose: Purchasing a Scissor Lift that can handle heavy weight and that comes with huge extension may go a waste if your requirement is just to transfer the loads from the truck to a smaller warehouse with only one level. There is no need of a great extension. A simple lift could satisfy your purpose. So understand the purpose before you go for it.