Material This multifunctional 4-in-1 portable altimeter, barometer, compass and thermometer is made of high-quality metal + ABS material, which is lightweight, overall beautiful and easy to carry. It is an ideal product for outdoor enthusiasts. The multi-function altimeter displays your current altitude, keeping you informed of your altitude; the barometer and thermometer can help you anticipate changing conditions and anticipate sudden changes in weather by keeping an eye on air pressure trends. Helping you take the necessary precautions to ensure your trip is safe and successful. Direction Guide This mountaineering hook strap is equipped with a compass, which is sensitive and accurate, so you will never get lost. Special technology is used to improve sensitivity and accuracy. This beautiful compass will always guide you in the right direction. How to use Before climbing, if the altitude of the starting point is known, adjust the altimeter pointer to the scale of the known altitude. In this case, the measured data is the true height of the mountain. If you don't know the altitude of your starting point, adjust the altimeter needle to zero. In this case, the measured data is the relative height of the mountain, that is, relative to the starting point. This versatile barometer combines the functions of an altimeter, barometer, compass and thermometer. Specially used for outdoor sports such as mountain climbing, hiking, skiing, etc., it can increase and cultivate the fun and motivation brought by outdoor sports.