Fire domes to fit Adastra metal quick-fit ceiling speakers. These steel back housings create a fire-resisting barrier to protect the speaker and ceiling cavity in case of fire. Fire regulations for certain buildings may require fire domes to be fitted to ceiling speakers to help prevent the possible spread of fire from floor to floor and maintain the fire alert sound system. All steel construction. Minimal profile for shallow cavities. Supplied with ceramic terminal block. Suitable for Adastra quick-fit ceiling speakers (952.161UN & 952.163UN).