DKS 9200 Series Operators are designed for maximum security applications only – such as industrial locations, loading docks, factories, airport security areas, sea ports, etc. Because of the need to prioritize security in these applications, these operators are designed for fail-secure operation and require manual operation to open the gate in the event of a power outage. To enhance security, these operators feature an anti-tailgating circuit and an adjustable partial open feature to help prevent unauthorized vehicle access. In addition, speed controller options allow the user to adjust the gate speed from 1/2 ft/sec up to 4 ft/sec. An Emergency Close feature is available on some models which will close the gate at 4 ft/sec. This assures your security gate is open the absolute minimum amount of time necessary.