I bought the Tee Claws because when I go to the driving range I'm usually hitting off mats with the big rubber tees. I really dislike the rubber tees. The Tee Claw just screws into the mat and you place a wooden or plastic tee in the Tee Claw. It allows you to use different sized tees. Since the tees only go in about a quarter of an inch you can get rid of your old short tees. It comes with elastic tethers to keep the Tee Claws from flying away. I use a tee in the other end of the tether and stick it in the ground in front of the mat. Even if you like the rubber tees, they don't always have the right height or they are missing altogether. Well worth the money.
These are perfect! Great for alignment drills and holding a tee. Really grip the mat too! Excellent product.