I love these bits. I use them to make closet doors. After receiving them, I ordered a few more sets. They come in these cool, flexible, rubbery protective cases and do their job well. I didn't reply to the "instructions" because it didn't have instructions. If you didn't know how to use them, you probably wouldn't buy them. Also, I didn't comment on "durability" because I haven't used it often enough to have a link. I recommend these guys.