First anal toy

I’ve never done anything anal. Beside that mythic painful horrible time everyone has when the man in passion enter the wrong hole. And you more or less die.

We sort of tried once but trying penetration didn’t convince either of us. The thing is I’m really in love with these butt plugs that are cat/fox tails, and want to try one. I’ve seen there are different sizes but I don’t get what the measures are from.

Can you explain how do they measure this? Have you tried this? Do you thing is a good first anal toy?

Thank you so much 😊