tecnifibre black code 200m rulleBlack Code is Tecnifibre's best selling polyester tennis string. It provides good control and generates a lot of spin due to its 5 edge structure and it is both softer and holds pressure longer than comparable strings on the market. Durability: very high Playability: high energy on returns Arm friendliness: medium absorption of vibrations With Thermocore technology (High Crystallinity Degree Process Polyester), a process that provides flexibility