I bought a set of 11. I have the following sizes: 1/8, 3/16, 1/4, 5/16 , 3/8 , 13/32 (?), 7/16, 9/16, 5/8, 11/16, 3/4 So the 1/2" collet was not included. I'm pretty sure they accidentally entered 13/32 instead of 1/2 inch. I found it easier to just order a 1/2" collet ($16) than mess with the return, which I did. But it was a bit annoying to have to pay extra for the whole set. The rest of the set looks good, seems to work as expected.