1. It can be pushed by hand or pulled by chain. During hand pushing the pull chain does not rotate. 3. Pull down the lower beam, the roller blinds will fall, and stop when you release it; lift up the upper beam, and the roller blinds will rise, and stop when you release it. 4. Roller blinds can be stopped at any height. 5. By adjusting the number of pre tightening turns of boost spring, the rising speed of roller blinds can be adjusted. 6.The system is equipped with limiter, which can limit the up/down position of roller blinds. 7. The clutch used mental core technology.