I am looking for something that has some kind of grip on the bottom so it won't slide around.

Our Eco-Soft + tiles are made of closed-celled EVA foam and have a smooth bottom surface. Because these tiles have a smooth bottom surface, during certain movements these tiles can move. We recommend the use of a double sided tape to help prevent this. For a product that is more slip resistant, we do offer a wide range of rubber tiles that will stay in place during many different types of exercises. Our most popular tile for home gyms is our 8mm Strong Rubber Tiles.