https://vedardalarm.com/waterproof-24v-conventional-fire-alarm-horn-strobe-sounder-p-243
This is kind of manual outdoor sound and flash strobe siren optional, it is suitable for fire, medical, patrol etc, It used high quality LED flash lights and Ultra sound loudness piezoelectric device, with high conversion efficiency for photoacoustic, electricity.

Technical Description
1.Operating Voltage: DC12-30V
2.Operating Current: ≤40mA(according to working way)
3.Temperature: -20℃ ~ +60℃
4. Operating Humidity: 0%~95%RH
5. Sound pressure: ≥105dB (at 1meter)
6.Net Weight: 360g
7.Flash intensity: >=1.2WS
Product Features:
1) Equipment operation stable and reliable;
2) Equipment easy to install, wiring;
3) Equipment has also issued two kinds of sound and flash an alarm signal, even people with disabilities can be a timely response to evacuate;
4) When the device is different emergency situations, a variety of alarm options;
5) Sound pressure level can adjustable.