20 by 20 mm star ring

the whole maths of naming a ring is so confusing and complex one place it's called one thing another place another thing so I'm going with the keep it simple stupid method of not saying it's sized T which it is in some places but giving the measurements. edit it here online https://tinkercad.com/things/bL5Rbh4EwGq-star-ring
learn about ring sizes here to make ring in your size http://www.thingiverse.com/thing:12689
p.s. made with http://www.thingiverse.com/thing:284644
on tinkercad