The Auxx-Lift can be mounted on any ceiling (rafters/joists/sloped ceiling) THIS KIT IS OPTIONAL: Usually the lift's motors run parallel on the ceiling joists. In order for you the motors to operate perpendicular for your joists you may need this package. This additional package will change the System ninety Degrees https://auxx-lift19764.wikilima.com/1405380/not_known_factual_statements_about_auxx_lift