wireless keypad widely used in gate opener and garage door opener 
General remote copy supported.
Product material:ABS
Product color:Black or brown 
Installation:wireless
Radio transmission distance:30-100mm(open area)
Scope of appliciation:garage door,alarm,automatic door,rolling door,etc.

So it works for safety,very important for garage door system safety protection.
Garage door can be dangerous task. Garage door springs and cables are under
extreme tension and require appropriate safety precautions. Working with
garage doors and openers could result in personal injury or death. We recommend all installations,
repairs, adjustments, and removals on garage doors be made by a qualified
garage door technician. Any attempts to install, repair, replace, adjust garage
doors or openers are done at your risk.