ارتفاع قوة الدفاع الجوي تحذير من متحدثي قرن الألمنيوم

High Power Air Defense Warning Aluminum Horn speakers Air-Raid Siren Speaker can deliver clear voice messages to large, outdoor environments. This product can be customized to address any site specific need. siren speakers are ideal for rural broadcast, early warning, natural disaster emergency early warning, emergency response policy content publicity, agricultural science and technology publicity, get rich information broadcast, village regulations notice, construction site to achieve...