DoorKing 9555 Maximum Security Slide Gate Operator DKS 9555 Series operators are designed to operate large vehicular sliding gates weighing up to 10,000 Lbs. These operators have a variable speed drive with slow-start / slow-stop circuitry. An optional 10 Ga. heavy-duty steel housing is available. A chain support tray is recommended for gates exceeding 20 feet in length. These operators include a mechanical disc braking system. A disc brake auto-release system can be factory ordered with this operator.