This product features an integrated altimeter, barometer, thermometer, and compass. It is constructed from high-quality, durable materials resistant to tears, impact, pressure, cold, and heat, making it suitable for various harsh environments.The altimeter and barometer include a built-in sensitive air pressure sensor that measures real-time atmospheric pressure. Since altitude is inversely related to atmospheric pressure, it can accurately measure relative altitude. After proper calibration, it provides real-time altitude readings.Combining barometer, altimeter, thermometer, and compass in one tool, this device requires no battery or charging, eliminating the need for power maintenance. Its mechanical design ensures reliability and durability, making it an ideal outdoor companion.The barometer helps predict weather changes based on atmospheric pressure trends, allowing users to prepare in advance. Compact, lightweight, and thoughtfully designed, it offers convenience and practicality for outdoor activities such as mountaineering, climbing, skiing, and hiking.This eco-friendly instrument features a pure mechanical structure, designed specifically for outdoor sports enthusiasts. It serves as a reliable partner for all your adventures and is an essential tool for outdoor exploration.