If you do not have much room above your coop door, or you need the door opener to sit much higher than the door, you may want to set up a pulley system.
Before setting up a pulley system, ensure the following:
your coop door weighs a maximum of 1.5kg (3.3lbs)
you use no more than 2 or 3 pulleys
you remove the bead from the string
you ensure the unit is set to Manual Calibration
you use eye screws instead of traditional roller pulleys
(Traditional roller pulleys add extra resistance in the movement of the string, and can cause the door opener to go into an error state.)
NOTE: ChickenGuard do not sell pulleys, but they can be purchased from hardware stores and online stores like Amazon.