TWO markers in ONE - The only patented 3 Dimensional dome marker and coin marker. The dimpled black marker helps you visualize your ball and line while you are waiting for your turn to putt. Great for tournaments, events, and everyday use. Become a more confident putter and shoot lower scores. Endorsed by US Open Champion and Ryder Cup Captain Jim Furyk. Approved by the R&A and USGA, this revolutionary three-dimensional domed golf ball marker enhances focus on the green. Humans are 3D creatures living in a 3D world, but our eyes capture only two-dimensional images. Our brain creates depth perception by combining two slightly different images from each eye, a process known as stereoscopic vision. Because our eyes are spaced apart, each retina receives a unique view. The differences between these images correspond to the depth of objects. When processed by the brain, this information is interpreted as depth. In putting, accurate vision is essential to identify the aim point, align the putter face, and judge the distance between the ball and the hole. However, peripheral vision can create distractions. The 3D marker helps golfers focus sharply, promoting intense concentration and a "tunnel vision" effect that boosts confidence and improves putting performance.