Handle and Cranking Lever Folds. No Power Supply Required. Compact for Portability. Powerful Universally Recognized Sound. Manual Hand Crank Operated Air Raid Siren. Produces a loud adjustable sound of 110 decibels. Made out of durable aluminium alloy. Ideal for attracting attention, supporting your favorite team at sporting events, and various other applications. By manually rotating the handle, the gearbox accelerates to produce sound; the sound level depends on the rotation speed of the handle. Operation: Manual hand lever operated Sound output: 110 dB o frequency: 550-2000 Hz Transmission distance: 1000 m Color: Red Material: Aluminum alloy Package Contents: 1 x Hand Crank Siren Horn Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture to be slightly different from the real thing. The measurement allowed error is +/- 1-3 cm.