This type can also be used in trucks, trailers and some buses. These types, called as Metal Air spring have a top crimping plate which fastened the air spring to the chassis. The bottom plate helps air spring to attach to the piston on the axle connection point. Due to fluctuation in the weight of a truck, and thus the axle load, and based on the payload at any given moment, air spring is used to ease the transportation of fragile goods and to protect the vehicle body, which in turn ensures safe driving regardless of the loading conditions. Loading capacity of air spring can go up to 4,5 tons and can operate at up to 700 mm operation height and work functionally under low temperatures (-40°C) and high temperatures (70°C) like all air spring types.