Oh that's great if he's not flying off the wheel
. Harmless - it's correct that flying saucers aren't good as a main wheel for a Syrian hamster - but they are fine for dwarf hamsters who are much smaller so can run straight on them. Syrians can run at a funny bendy angle on a saucer if not using it properly. So a main wheel for a syrian should be an upright one ideally - although a saucer is fine for an additional wheel (most people don't have room for an upright wheel AND a 12" flying saucer!). Or for out of cage time in a playpen eg.
Robos absolutely love saucers. As well as upright wheels. As their wheels and saucers are smaller I had both in my cage and our robo would go between them - you could literally see him smiling lol. He also seemed to like sitting in the middle of the saucer after a run. But its an optional bonus rather than a necessity.