The piston rod is not allowed to rotate, and the function of non-rotation of the rod can be selected low profile rodless air cylinder; heat-resistant cylinders should be selected in high temperature environments; corrosion-resistant pneumatic rodless actuators should be selected in corrosive environments. In harsh environments such as dust, a dust cover should be installed on the extended end of the piston rod. When no pollution is required, oil-free or oil-free lubrication rodless should be selected. The size of the selected rodless actuators cylinder diameter is determined according to the relevant load, air pressure and direction of action.