Material: Acrylic;Temperature Range: 20 - 50 Degrees Celsius;Neck Lanyard Length: 42.5cm/16.73" (Approx.);This multi-function whistle is not only lightweight but also portable, pocket size with a key ring, more convenient to carry and hard to lost, simple but practical;Emergency survival whistle is suitable for outdoor activities such as hiking, fishing, camping, boating, hunting and also for lifeguards, pet dog training, etc;This versatile whistle can be applied when you occur an accident or in distress while hiking, camping, climbing, fishing, boating, biking or any other outdoor activities, also suitable for daily use;3 in 1 multi-function emergency whistle,3 function: whistle, themometer, compass, Durable plastic whistle and nylon neck lanyard,On one side there is a compass, and the other is Celsius thermometer.