The benchmark for medium gauge strings, the Babalot VS Touch Natural Gut string utilizizes premium materials and new technology for improved playability, power and comfort. BT7 technology is a new layering structure that Babolat claims will increase durability by 15%. The string also features Thermogut coating to resist heat and humidity. Excellent tension maintenance, superior feel and now offered in black. Gauge: 16/1.30 mm.Color: Natural, Black.Length: 40 ft.