Product Material: Aluminum alloy Color: Red Dimensions (approx.): Length: 115mm Width: 202mm Height: 9.1 inches Operation: Hand lever operated Sound output: 110 dB o frequency: 550 Hz Transmission distance: 1000 m Handle and crank lever folds for compact storage No power supply required Compact and portable Quantity: 1 piece Delivery content: 1 x Air alarm The hand siren crank operates manually without a power supply. This manual air raid siren features a winch drive mechanism that produces a loud sound of 110 decibels. By turning the handle, the internal gears accelerate to generate sound, with volume and tone varying based on handle speed. Compact and portable design with foldable handle and lever for easy transport. Includes a hip pouch for convenient carrying. Constructed from durable aluminum alloy for long-lasting use. Delivers a strong, highly ble signal ideal for outdoor events and emergency situations. Ideal for attracting attention during sporting events, emergency drills, or outdoor activities. Effective for crowd control, safety alerts, or team support in various environments. This hand-operated siren produces a powerful, adjustable sound reaching 110 decibels, suitable for use in schools, refugee camps, or public gatherings. Whether used for cheering or signaling, it provides reliable, high-decibel performance. Rotating the handle drives the gearbox, progressively increasing gear speed to generate sound. The output level depends directly on the rotation speed of the handle, allowing user control over sound intensity.