What a great product. I use many different black lights on a daily basis. The light bulbs they replace are fluorescent tubes. These LED bulbs are so superb. They use much less energy. They produce much less heat. They get brighter, brighter, and the "visible" light shines more evenly. The lamps inside are not painted or stained. Simply clear glass bottles. Bases fit US standard mounts. They are amazingly easy to install. And their prices are so affordable. I can't comment on the durability of the lamp, but when I use other LED lamps they last for years.