Application: This Fast response and precision engineering fits for car, watercraft, boat, caravan and truck. Convenient to Use: Adjustable mount bracket and visible lubber line for easy direction reading.Bracket mounted ,can be mounted on deck allowing to remain at proper viewing angle for the accurate directions. Precisely: Built-in accuracy compensator to easily adjust for deviation, which makes the reading more precisely. Design: This is designed for car, boat or watercraft and the reading is totally opposite to normal . For example, when you are towarding the North while the is placed in front of you,you will face the "N" in front of you and the "S" pointing north direction. Material: Made from ABS, this is waterproof, resistant, so that it is very suitable for sea boats or marine vehicles. Please Note: The product is magnetic field sensitive. The deviation will be caused by changes in the magnetic field of the use environment. Need to be recalibrated for environmental bias.