You cannot choose the shape, but you can choose the crystal. (the reason for this is that the stones are irregular and also the holes sometimes it has mind of its own and turns out way different than expected because of the orientation. I ask for your understanding and only purchase if you welcome surprises).
Tip:half sizes are available just send a message after ordering if you want a half size.
if you are thinking twice whether to get a size bigger or a size smaller, I suggest you get a size smaller. Since the band is thin, it tends to feel a little loose that it actually is. Average Asian size is 4-6
NOTE:If you chose a size, ring will NOT be adjustable