automatic operato,Controller,up and down hanging,motor equipment, pully parts,door suspension and carrier parts,Belt bracke ... lock(optional) Ø Self-check and display error code by LED Ø Motor run smoothly & safely Ø Big size wheel(high quality POM material) Ø Easy ... install on top or on side direction Ø Motor,ntroller,lt free to maintenance Ø Special three wheel hang device ...