The Ultra 100/100L/100UL Bumper and Grommet Replacement Set extends the life of your racket and strings, protecting the frame against abrasions with the court surface and the strings against premature breaks. An ideal replacement for bumper guards showing signs of wear with cracks and scuffs or grommet sets with missing or split grommets, this set will both strengthen its frame protection and reduce friction between the strings and the frame.