Can be wirelessly interlinked with up to 50 FireAngel Smart RF devices, including the FireAngel Connect Gateway (also compatible with Wi-Safe 2 products)Wireless interlink technology built-in (does not require a separate Smart RF module for this product)Mains powered with sealed rechargeable back-up battery.CE marked.Radio-frequency range: 200m in free space, 35m in buildings.Suitable for those who are deaf or hearing impaired.Test function: able to test all interlinked alarms from a single location.Can be wall mounted or left free standing.5 years manufacturers warranty.