The screw-on backs are TINY! They are literally half the size of a grain of rice. I bought the 5mm set. The stone and setting are fine. But I cant even take them off the gift box because I cant get a hold of the tiny backs.

Update: I finally got them off the box and tried them on. I cant get on the backs that came with the set because they are so small. I tried another backs from my jewelry stash and found that these posts are very short and I cant use them with different backs.