Trade name: 3 decibels (1 decibels)mouthWhistle, thermometer, compass)

1. North (south) needle (high accuracy, clear and clear)

              2. Thermometer (faster and more accurate first time to grasp the current temperature)

              3. Carry a thermometer on one side.With a compass on the other side:

4. Nylon hanging rope (it's more convenient to carry around,Rope length about 40cm (can be hung from the neck)

             The whistle is loud 

Weight: about 20g
Product length: about 63mm

Product width: about 30mm