Gate Control : A gate operator is a mechanical device used to open and close a gate, such as one at the end of a driveway. There are two main types of electric gate openers – hydraulic or electromechanical; these can be further split into the following categories, worm (or screw) driven, arm openers and underground openers. Automatic and Electric Gate operators are designed for both swinging and sliding gates. They can be programmed to open and close with a wireless transmitter or a manual device.