Square-grooved clubs such as the PING Eye2 irons are banned by the USGA, which claims that tests show the clubs give an unfair competitive advantage to PING customers. The PGA Tour also bans the clubs in 1989. Karsten Manufacturing, maker of the clubs, fights a costly two-year battle with both the USGA and the PGA Tour to have the ban rescinded after winning a temporary injunction. Eventually both organizations drop the ban, while Karsten acknowledges the right of the organizations to regulate equipment and pledges to make modifications to future designs.