I needed very small diameter drills for scale modeling. A few months ago I bought a pin vise and used the small set of attachments that came with it. The problem with these bits is that they are either very dull or don't have a decent cutting edge. I started looking for a replacement when I came across these little CNC carbide bits. They all have a 1/8" shank that fits in my pin vise. I couldn't find any quality standard bit sets at a price close to these so I decided to give it a try. My god I was in for a surprise !These nozzles are made from semi-rigid thick plastic.The case alone is approximately 3mm thick and not a cheap throw away item.This is a fantastic case that seals securely yet is easy to open.Inside the case the bits are on one removable strips of the same plastic as the case. The band doesn't take bits at all. It's not a friction fit where you press them into place. Literally instantly. Knowing my occasional clumsiness, I decided it would be best to use the strip to attach to the case. The strip just sits on three small pins protruding from the case back. I applied a good coat of medium weight glue (Gorilla S super Glue is almost medium for reference) glue along the back of the strip and let it fall onto the small pins. Now the bar is safe, but if you open the case and turn it upside down, all hit points will fall. So keep that in mind. These bits start at 0.1mm and go up to 1.0mm in 0.1mm increments. So you get 0.1, 0.2, 0.3 and so on. When I opened it for the first time, I was completely shocked at how small 0.1mm really is. This part can hardly be seen with the naked eye. I was just amazed that technology could do something like that. You can drill 2 holes side by side in a human hair. I'm not exaggerating. I could tell the instruments on these beats were top notch by looking at the big sizes. No tool marks, no burrs, no scratches, nothing! Out of curiosity, I pulled out my microscope to look at the 0.1mm drill. It was pristine and looked just like the other nine bits. Even on this scale there was no loss of quality. Knowing how difficult it is to get other drills to drill through my styrofoam models, I grabbed a spare sprue and decided to give it a try. The bits have a color matched ring that works perfectly as a retaining ring for my vise to keep it from being pushed further into the vise. I started drilling and to my amazement a perfectly curved plastic rod spiraled out of the hole showing that the drill bit was so sharp it cut through the plastic like a hot knife through butter. There is almost no resistance when drilling because they are so sharp. Actually used a little today and just for fun I didn't use a pin vise. I only used my fingers. It worked like a champ! I couldn't believe it! I have never had a drill that cuts so cleanly and effortlessly and have been a professional salesman for industrial supplies (drills, tools etc.) for 25 years. The beats I compare them to are considered the best in the world. However, comparing these bits to industrial 135 degree jobber bits is like comparing apples and oranges. But for my purposes, this little set is a clear winner. If you are interested in modeling, buy these beats. If you build printed circuit boards (PCBs), buy these bits. If you enjoy crafting little things, building dollhouse furniture, or doing something else in miniature, buy these pieces. You'll be amazed.