Centrifugal type open mechanism can guarantee that the sutters comletely open and close, Make the shutters opened to reduce, increase the air flow: Closed tight, can effectively prevent the outdoor wind, light and dust from entering the house; The first use of hight-quality nylon PA66 material, to ensure the servile life of the open mechanism: Centrifugal type open parts are connected, use copper rivets link, wear resistance, no rust, good flexibility, reduces friction coefficient: Guide rod made of 304 stainless steel, plus special material, ensure the intensity, not rusty, greatly improving the service life.