Feel light and move lightning fast. The Viper SL is a more flexible, breathable and lighter version of the Viper. Air mesh has been added on the upper part of the shoe to provide maximum breathability and comfort. Viper SL also comes with a new tongue construction for a comfortable fit and the stability you need on the court. The lower part of the shoe has all the features of the Viper and the construction gives a nice and snug fit and keeps the foot in place properly.