This system contains the volume film, pinion and rack window, and air sliding window. The three types system has its advantages. You can choose according to your local need to achieve the practical effect.

per the plastic film;
we own the high quality plastic films of various types.  It uses materials between simple oxidation resistance steel pipe and belt zipper of polyvinyl chloride (PVC) film. This film can be rolled up, and has the ventilation function.