Those of us who own (or use) a Monster Mat know that it comes with two tee holders that sit flush with the top of the mat. And this is great for those who want to use tees when practicing. However, you have to chase down the tee every time you hit the ball, and have to set the height correctly every time (unless you use something like a castle tee). If you want to use a rubber tee with the mat you'll discover that the diameter of the hole is smaller than normal. Most rubber tees won't fit through the hole in the mat so you're SOL unless you want to cut the hole bigger. These specific rubber tees are smaller diameter than most others and will fit through the hole in the Monster Mat with a little effort. I don't know about the durability of these tees because I haven't had them for long, but I suspect they're a little less than wider tees. But they seem okay and should last long enough, especially since you get five in a pack--perhaps several seasons.