This DIY wireless security system is easy to install and ready to use. It is a 4-zone system is designed for houses up to 3000 sq. ft. , plus apartments, condos, offices and businesses. Uses rolling code technology for maximum security and fewer false alarms. Emits a piercing 110dB siren and sends signal to emergency dialer (Item# 17615, sold separately) to call preset phone numbers. Up to 100ft. range. Lighted keypad with chime, instant and delay modes. Low battery indicator. Can be customized to fit individual needs. Includes control panel, motion sensor, 2 door/window contact sensors, keychain transmitter, AC adapter, batteries and mounting hardware.