The Ajax EN54 FireProtect (Heat/Sounder) Jeweller is a wireless heat detector with an integrated siren, designed for EN 54-compliant fire alarm systems. It operates using the Jeweller radio protocol with encrypted two-way communication and provides a wireless range of up to 1,700 m in open space. Two thermistors compliant with EN 54-5 (classes A1, B, and C) ensure reliable detection of dangerous temperature rises, while the built-in siren of up to 95 dB delivers immediate on-site acoustic alarm notification.