I have two mats. One is gray the other green, by Omnigrid.. Like that the Omnigraid the best. It's a circle and has "bumps" to slip your finger into for rotating.
https://themakersemporium.com/produc...ng-cutting-mat
However, I have a 12" square mat that I use more often. Doesn't rotate. Just a simple mat that does the trick and much cheaper.