- Built-in tamper-proof 10 year lithium battery
- Wireless interlink technology to connect up to 20 units
- Extremely loud warning tone
- 10 year warranty
- Large hush/test button
These photoelectric alarms features the Arma Intelligent Wireless Interlink Technology which allows up to 20 units to be wirelessly linked to protect the whole household. When one alarm activates, the entire network activates. Suitable for living areas, hallways and bedrooms.