The SENTRY 4 Zone alarm panel is a cost effective standalone security system, that can be used in any application that requires security. A GSM of Radio Transmitter can be connected for off-site monitoring. The SENTRY 4 Zone is a self contained control unit with power, arm/disarm, bypass and zone led's on the front of the housing._x000D_The unit can be armed or disarmed using the onboard receiver (transmitter included) or and externaly connected keyswitch. Bypassing of the zones are done on the remote.Up to 15 remotes can be programmed into the system. No configuring of the unit is required after installation, making it an easy installation.