To gather team members, to call someone, to call for help, to strengthen the security level in outdoor activities.
L x W x H = 55 x 15 x 8 mm
● Aerospace Aluminum High-frequency Whistle with Double Cavities
● Two cavities shaking together make it much louder than an ordinary whistle, and reach 120dB at maximum.
● With a high frequency of 3-4KHz, voice of the high-frequency.
● Little labor from you, big voice from it. It can help you to save at least 30% of your labor than that of an ordinary one.