Tecnifibre Tennis String Thermocore 4S - Black - 1.30 - Polyester

The 4S string is engineered to deliver exceptional spin, offering the highest level of effect in its range thanks to its precise square construction. Built for heavy hitters and advanced players, it provides explosive spin potential while maintaining the trademark Tecnifibre balance of performance and comfort. Designed with high-quality co-polyester and manufactured in France, the 4S string ensures durability, flexibility, and optimal feel for players who demand extreme spin without sacrificing playability.

• Maximum spin generation with square-section construction
• Ideal for advanced, demanding players
• Excellent for heavy lifters and topspin-focused playstyles
• Durable co-polyester composition for long-lasting performance
• Thermocore technology for improved flexibility and reduced fatigue

Who is the Tecnifibre Thermocore 4S best suited for?

Polyester (co-poly) is the choice for advanced players with full swings who want control, spin and durability. It's best suited to mature players - we don't recommend full-bed polyester for juniors or anyone with arm issues.

What does the 1.30 mm (16 gauge) gauge mean?

The 1.30 mm (16 gauge) indicates the string's thickness. This is a thicker gauge, which trades a little feel for extra durability and tension stability.

What tension should I string it at?

The recommended tension range is 48-55 lbs (22-25 kg). String toward the lower end for more power and arm comfort; higher end for tighter control.

How long will this string last?

This is a durable string that should last most club players 25-40 hours of play or around 2-3 months of regular use before losing pop.