Vibra Worm - 6 Pack - Gel Filled Long Tennis Racquet Vibration Dampener - Premium Quality - 2018 Model - Thousands Sold Gel Filled Vibration Dampener Covers 5 or 6 strings for more vibration reduction Economical 6 pack - 3 Black, 1 Yellow, 1 Red, 1 Blue Identical to Gamma Shock Buster Please do not over stretch during installation