A. appearance novel, edge and corners clear, strong stability , run stably
B. Use the aluminium or polished steel as door body ,line succinct ,elegance appearance ,to arrive requirement of construction or humanity culture .
C. Use the newest steel runner as the door body runner ,firmly ,durable
D. Use the needle bearing as ground-driven reel ,which can run stably under the great pressure ,also can prevent the ground-driven reel from damaging because of the rusty bearing .
E. Wheel cover has broken the original signal appearance and make the door full and dynamic base on the construction principle and esthetics.