Multi-function - This professional military grade dashboard altimeter compass will always guide you in the right direction. Suitable for car, watercraft, boat, caravan and truck and wherever the beaten path takes you High Accuracy - Built-in precision compensator to easily adjust the deviation, making the reading more accurate, improving its precision and decreasing its errors Navigation Compass - Easy to install and visible lubricant line for easy reading of the direction. The compass pointing direction is the same with the vehicles' course. Made of high quality materials, waterproof, corrosion resistant Bracket Design - Bracket mounted compass, can be mounted on the deck or dashboard; allows the compass to stay at the appropriate viewing angle. Medium size bracket holder, more stable for navigation course changes Great Balance & Portable - The car gyroscope compass owned fast response, high sensitivity, keep balance individually, precision engineering reading display. Compact size, this compass is very portable and easy to install or use