Invasion Silicone Urethral Sound Trainer Set
[AE720 Urethral Sound Trainer Set]

Pros: Flexible, Smooth/soft, "pretty"

Cons: The larger ones are intimidating since they're twice the size of the smallest.

This is new territory for me, so my review is from the view of a beginner. These are pretty simple: lube them up and insert them. Clean up was easy as well, since there are no textures to speak of. They're flexible and as comfortable as I could imagine this sort of thing could be. The flex on the smallest size was enough that I was actually uncertain when to stop inserting: there was no twinge of pain or discomfort. I think the size progression is probably about right if you wanted to work up to the biggest.