I have the large Martelli Roundabout. It's very old and I'm still using the same mat. It sure has held it's quality. I use it all the time. I like it as it does not tip when cutting pressure is put on the edge of it. I also have a 12 x 18" inch rectangle rotating mat frame made by Elna. It is one handy dandy thing and always a Where did you get that? at retreats. LOL Any 12 x 18" mat will fit it.