Experience explosive spin and refined power. The Signum Pro Thunderstorm features a unique 10-sided, axially twisted profile designed to bite the ball for maximum RPMs. Built from a high-elastic co-poly, it bridges the gap between stiff control strings and comfortable performance, offering a crisp feel with elite tension stability.

Key Features

High Elastic Co-Polyester Construction: Developed using Signum Pro’s specialized heating process to provide a more flexible, lively response than traditional, stiff polyesters.

Balanced Power and Control: Engineered to offer a “spring-loaded” effect that boosts ball speed while maintaining a predictable, controlled trajectory.

Crisp, Comfortable Feel for a Poly String: Offers a distinct, sharp feedback at impact while significantly reducing the harsh vibrations often associated with control-oriented strings.

Good Durability and Tension Stability: Features high molecular cross-linking to ensure the string retains its playability and “snap-back” longer than competing co-polys.

Ten-Sided Axial Profile: A unique twisted, decagonal shape that enhances grip on the ball for massive spin potential without sacrificing the consistent feel of a rounder string.

Best For

Intermediate to advanced players seeking a powerful, all-purpose polyester string that offers elite spin potential and an arm-friendly, forgiving feel.