The Chamberlain Group, Inc.
845 Larch Avenue
Elmhurst, Illinois 60126-1196
www.liftmaster.com
GARAGE DOOR OPENER
Model 3850
For Residential Use Only
Owner’s Manual
■
Please read this manual and the enclosed safety materials carefully!
■
Fasten the manual near the garage door after installation.
■
The door WILL NOT CLOSE unless the Protector System
®
is connected and
properly aligned.
■
Periodic checks of the opener are required to ensure safe operation.
■
The model number label is located under the light lens on the left side
panel of your opener.
®
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