the KJ500, KJ600 and KJ1000 rolling door operators are designed to drive rolling door (rolling shutter) from 500kg to 1000kg. the products featured with powerful starting strength, overworking for a short time and overheat protection when overloaded. In case of power failure, a release chain can be used to operate the door manually. Advanced Features Loading up to 1000kg Available in 3-phase (KJ600 & KJ1000) Limit switch unit enables precise adjustment of door in up and down positions Overheat protection Electric and manual operations Release chain in case of power failure Control panel wiring are available to infrared photocels, alarm lamp and remote controller Special designed safety device prevents vehicle or people from damage in case of roller chain is broken off