Was looking for thin drill bits and damn these things are thin. What I love about these drills is that they come in a box so they can be stored away when not in use. When I used the thinnest I had a feeling they were about to break but I'm amazed at how durable they are. I really like that the bottom is thick so it can be used with almost any drill bit. It took me a little twice as long, but I understand that the longer the bits can break. Glad I found a way out and it was really helpful for my project. I would recommend them to anyone looking for durable thin drill bits.