KATSU Hand Crank Siren, Portable Manual Operated Air Raid Siren Fire Emergency Safety Alarm 110DB 550HZ 2.2kg with Bench Clamp Mount Aluminum Alloy 990633

• Manual Hand Crank Operated Air Raid Siren
• No Power Supply Required
• Powerful Universally Recognized Sound?Produces a loud adjustable sound of 110 decibels.
• Ideal for getting peoples attention, or rooting for your favorite team in sporting events, and many more applications
• Compact and Portable, Sound Rating:110± 2dB(A) @ 1m, Effective range(Diameter): 1000m

Specifications: Sound Rating:110± 2dB(A) @ 1m Output Frequency:550±20Hz (depend on the speed of the hand) Effective range(Diameter): 1000m (in the open environment) Net Weight: 2.2Kg Features: No Power Supply Required. Compact for Portability. Bench Clamp Mount. Powerful Universally Recognized Sound. Manual Hand Crank Operated Air Raid Siren. Produces a loud adjustable sound of 110 decibels. Made of durable aluminium alloy. Ideal for getting peoples attention, or rooting for your favorite team in sporting events, and many more applications. By manually rotating the handle, the gearbox of the transmission step by step acceleration to achieve the purpose of sound, the sound depends on the rotation speed of the handle.