The inside is smartly protects the bulbs as well. These bulbs are making me happy in that regard big time. They are not hugely powerful, possibly wouldn’t use them alone as a single bulb on the ceiling for a big living room, but still good for many other uses. Its base is E27 . I had to buy socket to convert into B22 base but it's worth it. I needed 6. 3 for the living room and 3 for the staircase. It was a bit dark before and now everything lite up. Good quality for the price.