This set contains LOTS of drills. They are way better than I expected, especially considering the price. There is a wide range of bit sizes, from around 3mm to hair size. I have several pin vises and this is by far the best set, it has the best build quality and drill bit rating. The pen and bit storage is well designed and the bit holder is solid but difficult to open. BUT you can rest assured that it won't accidentally open and spill on you. Some are so thin you can barely see them lol. The only downside is that if you really tighten the vise, the silicone on the handle can twist on you. They're not designed to pull very hard, but there are times when you need to get used to it, and in those cases the silicone grip can give a little.