"Power Supply: Low-consumption battery operation Notification: Phone call, text alert and 110db on-site siren Supports up to 8 programmable phone numbers Low battery alert via text message Radio Frequency: 868MHz GSM network:2G Transmitting Distance: ≤ 100m (open area / no interference) Mode: Arm/disarm/arm stay/arm away (SMS & phone call supported) Support customizing settings:Arming delay ,alarm delay ,alarm duration,alarm siren Operation Condition: Temperature -10°C / 14°F ~ +55°C / 131°F Built-in red LED warning light in the main unit Supports up to 32 accessories Customizable zone names via mobile phone SMS Supports up to 8 emergency contact phone numbers Support for delayed defense and delayed alarm Three CR123A batteries , on standby can last for up to 1 years"