aww i wanna help!
what do ya wanna use it for?
apparently cheap ones pop and stuff if you're a little heavy, but then if you go to a sports shop you'll pay lots for a good quality one!
if you wont use the arm things dont get them cause then they're just annoying!
and you should get whatever size for what you wanna use it for too! like if you want to put it between your legs get a smaller one, if you want to sit on it or balance on it get a bigger one
I'm no expert and have no idea what im talking about but i wanna help! haha