Parodia leninghausii.. I have one that seems to be putting on a growth spurt now when it is highs in the 70's and 40's - 58 at night. I take it in when it freezes with a few colose nights outside, but I definitely do protect it. It goes in and out in the winter here in Texas.

Nice plant there.

Here is a link that might be useful: Care recommendations

Thanks!

Looks like I've been bringing it inside too early.

Love those babies. I'd leave it like it is.