function, you can clearly see the time in no light at all. The duration is about 5 hours and it gradually become darker. At this time, you need to absorb the light again; so after you receive the product, please let it be exposed to the outside to absorb it. Do not block the light. It needs to be lighted to have at night. The it absorbs, the brighter it is! Use of function: The main raw material of is light-induced storage powder, which stores light after being irradiated by , fluorescent light, ultraviolet light, etc. Get up, after stopping the light irradiation, it is slowly released in the form of fluorescence, so you can see the light at night or in the dark. Quiet movement, accurate time, bid farewell to mechanical ticking, very suitable for home decoration, living room, bedroom, , etc. 12-inch silent wall clock, Battery Operated(need to bring a carbon 1pcs AA battery,not included) Fine workmanship, sturdy and , beautiful and generous, exquisite and fashionable, three-dimensional numbers, clear scale display, it also shows a strong visual and artistic effect