Corby Access Control Systems and Corby Keypads have been locking doors and protecting millions of people for over 35 years. We're so good at it that our customers put us in the same league as a Mercedes-Benz. We invented the first Digital Keypad back in 1972. Now we manufacture and sell simple and ultra-sophisticated systems to thousands of Security Professionals, homeowners, Fortune 500 Companies, the United Nations, US and foreign military services, NASA, the Secret Service and the FBI. We keep good company. This "stand-alone" access control system is designed for low cost and easy installation while only using a minimal amount of additional components. The model is 6520 Corby 6500 SA Programmable Keypad : Single Gang 2 LEDs. This "stand-alone" access control system is designed for low cost and easy installation while only using a minimal amount of additional components. Minimal operation only requires a 12 or 24 VDC power supply and an electric door lock