Product Material: Aluminum alloy Color: Red Dimensions (approx.): Length: 115mm Width: 202mm Height: 9.1 inches Operation: Hand lever operated Sound output: 110 dB Audio frequency: 550 Hz Transmission distance: 1000 m Handle and crank lever foldable No power supply required Compact and portable Quantity: 1 piece Delivery content: 1 x Air alarm - The hand siren crank does not require a power supply. Manual air raid siren with winch drive produces a loud sound of 110 decibels. By manually turning the handle, the gear system gradually accelerates to generate sound. The sound intensity depends on the speed of the handle rotation. - Compact and portable hand crank siren. Foldable handle and lever for easy carrying. Includes a hip pouch for convenient transport. Made of durable aluminum alloy. Produces a strong, widely recognizable sound. - Ideal for attracting attention during outdoor events, sports games, emergencies, or search situations. - This hand-operated siren produces a powerful, adjustable sound of 110 decibels, suitable for use in emergency alerts, schools, or cheering at sports events. - Manually rotating the handle drives the gearbox to accelerate step by step, generating sound. The output varies with the handle speed.