By law, all openers must be equipped with two auto-reversing safety devices. The first, known as a Contact Safety Reverse, automatically opens the door if it strikes an object or person as it's closing. If a person or pet passes under the closing door and breaks the beam, the door will automatically reverse. These safety devices can prevent serious injury, even death. So be sure to install and test them exactly as indicated in the owner's manual.
Convenience features .
Most units come with two wireless remote transmitters and a hardwired control unit that gets mounted to the wall inside the garage. Wireless keypads, invaluable to people who frequently misplace their house keys, are available for easy entry. The keypad is mounted outside the garage. To open the door, you just punch in a four-digit code. Security has become a major concern in recent years because of an electronic device called a code grabber.