This is a great HSS Hole Saw Set. In metric form, of course! Each bit is packed in a separate plastic case, nice too. The latch on them won't last long, but I won't scold them for it. The drill bits on each are sharp and look like they'll last a while. The teeth of the hole saw are sharp! I mean very sharp, ah! Didn't cut me, but still. Wow! Each bit also has its own hex key inside the housing. Nice to have if you're like me and the thousand Allen keys you have are always somewhere else. I plan to use them on aluminum project boxes, plastic project boxes and electronic lock boxes for inserting cable glands. it will hold onto something like steel, but if you're using it on steel cutting fluid is a must. Even with aluminum, a little lubricant is enough. The only thing that confused me was the nib, it's not in the picture but the nib was included with each attachment. It is arranged around the drill and extends almost over its entire length. . Perhaps the bit is too stable and creates counter-pressure? Most likely this will also help get what you cut out of the beat out of. I also took them off to test and forgot to check. In any case, this is a really good set and the price is great! I highly recommend them.