Chamberlain 8810CB 10-Foot, Compatible Whisper Drive Plus Models, Includes Replacement Belt Garage Door Opener Rail Extension Kit N/A Made in USA or Imported For use with Chamberlain Whisper Drive and Whisper Drive Plus belt drive garage door openers featuring the quick-install rail system. Works on garage doors up to 10 feet high Includes rail extension, replacement belt, and all necessary hardware New structural steel rail system Increases structural integrity