WRZ997114 - Luxilon 4G Rough Gold Tennis String Set - 16G (1.25mm) 4G Rough 125 is a textured version of 4G for increased ball bite and softer feel to go along with maximum tension maintenance for durability. By denting the string while it is still soft, Luxilon maintains the structural integrity and benefits of 4G string. With 30% greater tension maintenance, players using 4G Rough 125 can play better, longer. Wilson Luxilon 4G Rough Tennis String Set | Christy Sports