This product can provide electronic invoicesProduct Specifications:Type: Solar LED Traffic Safety SignWorking Mode: 12 hours per day or 24 hours per day, flashing or constant lighting optionalVisible distance: >2500 feetWorking Time: After one full charge, 5-7 consecutive daysLife Span: 3-5 YearsThe Dimensions: 24/30 inch Octagon Solar LED Traffic Safety Sign can be used on streets, in parking lots and more. U-shape Hoop mount (Customizable),Regular 76/89 (Please contact us if you need other sizes).Tips:1. Please install this sign where there is no shade from the direct sunlight.2. Please check whether the LED lamp can work normally before installation. First turn on the switch, then cover the solar panel to simulate the night state and see whether the LED lamp can work normally.3. The direction of the solar panel needs to be calibrated during installation. The best angle in the direction that can receive the longest direct sunlight in a day.4. Please clean the dust on the solar panel every 3 months to ensure that the solar panel can generate electricity normally.5. Please turn off the switch to prevent the battery from draining out if not in use for a long time,. It needs to be charged in full sunshine for 3 days before normal use if not used for a long time.