This fish finder's display is worn on your wrist, letting you move freely as you angle, unlike other sonar sensors with screens that must be handheld or affixed to a boat. It operates in a wide 75' remote radius, transmitting real-time views of fish and underwater terrain to the 1 1/4" LCD display. The sensor reads depth to 120' with a wide 90º sonar beam and also measures water surface temperature. Includes display backlighting and a pulse-lit advanced sensor for night fishing. All controls are easily accessed from the waterproof wrist unit that doubles as a wristwatch. The ABS plastic remote sensor runs 500 continuous hours, and automatically shuts off after removal from water. CR-2450 battery for wrist display included. 2" H x 2" W x 2 3/4" D. (1 oz.)