Simple activation/deactivation of the alarm system without a PIN code. With the key switch if the alarm system is activated and deactivated. A simple matter of the key replaces the entering a PIN code, which is a more comfortable and faster operation. Two extra switching contacts and color status LEDs next to the arming and disarming the alarm switching function of the alarm system (or individual parts), with the key switch also electronic devices (input lighting, garage, etc.) can be controlled. Here, there are two switching contacts, which can be set as a continuous contact or pulse contact. Two-colored LEDs inform each of the current status of the connected devices and whether the system currently is armed or not. Solid sabotage and weather protection. The high-quality, included in the scope of the cylinder, the core protection rosette as well as a stable weather-proof casing (IP55) protect the key switch from outside influences. The key switch is designed for semi-cylinders (10/30)