The compass is an important navigation instrument that uses the Earth's magnetic field to determine the main direction. Whether you are a weekend hiker, captain, or professional surveyor, a reliable compass can provide accurate directions when GPS signals fail or batteries run out.Mechanical outdoor compass uses the Earth's magnetic field to quickly indicate magnetic north, without the need for batteries, waterproof and shockproof, and is used for hiking, camping, directional off-road, navigation, and rescue; The electronic compass is used for real-time direction, latitude and longitude, magnetic field strength, and 15th weather forecast. Before use, calibrate the magnetic declination to ensure that the map direction is consistent with magnetic north, remains horizontal, and is away from metal/electromagnetic interference.