These are common in many houses and operate using whether button to open them as well as a sensor system, which unfortunately detects motion, opening providing access. Both will close automatically employing sensors to discover motion. Automatic doors of this type usually include a push button for a height suitable meant for wheelchair users and not only offer excellent fire protection but definately lets make a building accessible to your disabled. Again, they can be subject to abuse and may be propped opened, although this is less common than while using the manual type. My websites: north face outlet