The clock is plug-and-play and cannot be powered off when working. The pointer is adjustable (short press the black button on the back of the meter to adjust the time, or connect an external button to the black wire of the meter to adjust the time). The inst ent has the characteristics of high precision, long life, good shock resistance, waterproof and anti-fog. Specification: Operating temperature: -40°C ~+85°C Protection rank: IP67 Operating voltage: 9-32V DC Fixing dimension: 52mm/2-1/16 INCH Backlight: Red Scope of application: Universal for vehicles and ships Style: A / B / C Material: Plastic+stainless steel colour: As shown<br><br>Package Contents: 1 x clocks and watches Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.