Wilson NXT is the family of Wilson's premium string. NXT Control is an internal hybrid combining polyester and nylon fiber bundles with polyurethane. Polyurethane bundles provides excellent control, Nylon bundles provide comfort and forgiveness. Unique combination of Nylon, Polyester, and PU eliminates the need to hybrid separate strings. This listing is for 2 packs each 40 feet (12.5m) long. 16g (1.32) only.