The dunlop black widow 131mm tennis string 200m reel provides excellent spin power and durability for serious players who seek a deadly weapon that will help them defeat their opponents the black widow string has a name inspired by one of the most dangerous predators in the world and features a high tensile mono filament premium polyester construction that improves its durability it also has a heptagonal outer profile that helps generate an excellent amount of spin the gauge of the strin