1. For different buildings, the shuterss can be installed inside, outside or in the middle. Ithe shutters will rolled together to the upper part of the door, occupying less space of garage, and can prevent the mud, dirt and snow or rain from coming inside the garage. 2. The shutters will return automatically when unexpected trouble happened in case the door moving down to damage the vehicle and man, so that vehicle and man can pass without any worry. 3. The shutters are firmly and equipped with automatic alarm device, preventingagainst robbery or burglary, continuous alarming, ensures the safety of residence.