Wayfinder All-Terrain Auto/Marine Digital Compass Water resistant up to 10 feet in fresh or salt water; works in any vehicle Shock resistant built to withstand the rigors of outdoor or marine use Includes a 3-volt lithium cell battery and adjustable mounting bracket Measures 3.4 x 2.0 x 1.8 inches; weighs 3.4 ounces Patented Magnetic Sensor Technology