The Spider (indoor) model is fitted with hook-and-loop strips and works best when attached to felt or carpeted surfaces. Steel rods and foam bumpers work together to sharpen your aim and hand-eye coordination. Get meaningful repetitions of practice in while you’re in the office or home. Install the rubber bands and open whole world of games and exercises. The white ring that goes around the outside is the exact same diameter as a hole on a green which builds on your mental visualization. When an actual cup isn’t available, the white ring is the exact diameter of the real thing to reinforce consistent target recognition.