Tecnifibre Black Code 18(1.18mm) is the thinnest gauge of the Black Code family. Offering the highest spin potential and less durability in comparison. Utilizing a co-polyester core, this string possesses excellent durability with greatly enhanced tension maintenance and feel. Black Code 18 features a pentagonal profile, helpful for generating more spin as the string bites into the ball better. The string uses Tecnifibre's exclusive ThermoCore technology which serves two primary purposes. String to string friction is greatly reduce, enhancing durability and further promoting spin and ease of stringing. The ThermoCore technology also gives the string greater flexibility for more power and a softer feel. An excellent choice from all areas of the court with enhanced spin, good power, and a softer feel. Also check out the line of Tour-inspired Tecnifibre racquets.Construction: Extruded polyester monofilamentColor: BlackGauge: 1.18mm