Black is back. Tecnifibre Black Code 4S is a geometric monofilament polyester with a square cross-section. Like the original Black Code, Black Code 4S is produced using Thermocore Technology, a process that varies temperature in stages during manufacturing, allowing a softening of the matrix’s structure. According to Tecnifibre, this gives the string higher flexibility for greater shock absorption and reducing vibration.

4S stands for:

Spin — four sides as opposed to five in the original Black Code (see the July 2009 issue).

Speed — 20 percent more power than Pro Redcode (see the September 2006 issue).

Stability — The same tension maintenance as Razor Code (see the April 2013 issue).

Strength — 15 percent more durable than Black Code.

Tecnifibre developed Black Code 4S for high-level and competition players using racquets weighing more than 300 grams who are physically strong and want a string that provides spin, power and more durability.