Solar and Battery Powered Builtin solar panel and temperature resistant lithium battery. The car digital watch can be charged by solar power or by battery, providing flexible power options for reliable operation. Easy to Use Vibration sensor activated: The watch automatically turns on when it detects car vibration, such as starting or moving. It automatically turns off after parking for a preset period, saving energy without manual input. Sturdy and Durable Interior car design: The shell is made of temperature resistant material, so you don't have to worry about summer exposure inside the vehicle. Suitable for frequent use in varying cabin conditions. Adjustable Brightness temperature resistant LED digital tube display with auto brightness adjustment. Clear visibility in both day and night, with soft light at night and bright display under sunlight. Use scenarios Daily commute: Automatically powers on when you start the car and turns off after parking, providing time at a glance without manual interaction. Ideal for morning and evening drives in consistent use. Long drives and sunny days: Solar charging supplements battery power during daytime driving, helping maintain display readiness over extended trips while the interior remains visible and legible. Rideshare or fleet vehicles: Hands timekeeping with automatic on/off reduces the need to interact with the device, while durable construction withstands frequent cabin exposure and varying temperatures.