Feature: 1. Solid Structure: Crafted from aluminium alloy. Composed of a handle and an internal mechanical device, it generates a high frequency alarm when the handle is turned rapidly, effectively drawing attention in an emergency. 2. Compact and Portable: With compact and sturdy design, making it easy to carry and operate, it provides an effective warning in emergency situations, proving indispensable where there's no electricity. 3. Adjustable Volume: The volume can be varied, depending on the speed at which the handle is turned. The faster the rotation, the louder the sound, and a trigger can open the blades to amplify the sound even more. 4. Loud Alarm and Solid Construction: With an adjustable volume that can reach up to 110dB, the hand crank siren offers a sharp, penetrating sound with a large transmission range, making the siren durable and long lasting. 5. Wide Application: Ideal for use in various situations such as sudden fires, attacks, or emergencies, can also be used as a self defense tool, its manual operation allows it to offer an effective alarm without the need for a power source. Specification: Item Type: Hand Crank AlarmMaterial: Aluminium alloyWeight: Approx. 1833.00g / 64.66oz Mounting Hole Spacing: Approx. 60x60mm/2.36x2.36in Size: Approx. 205x198x115mm / 8.07x7.80x4.53in Communication Method: Sound Transmission Type: Wireless Alarm Host Alarm Method: On site Alarm Sound Pressure Level: 110±2dB(A) at 1m Sound Frequency: 550±20Hz (Depends on the speed of hand cranking) Structure: Aluminum Alloy Alarm Effective Range: Diameter 1000m / 3280ft Wide Application: Widely used in factories, homes, schools, oil depots, warehouses, flood prevention, disaster relief, public and industrial places, it can quickly alarm in emergency situations and reduce casualties and property losses. . Package List: 1 x Hand Crank Siren