Siux Electra Stupa Pro ST4 – Elite-Level Power, Control & Spin Siux Electra Stupa Pro ST4 (2025) is the latest signature racket from Franco Stupaczuk, built for advanced players seeking a perfect mix of power, control, and spin. Its hybrid teardrop shape and medium balance offer explosive shots with precision, whether you're attacking from the baseline or volleying at the net. Constructed with a 15K carbon face and EVA hard core, it delivers excellent ball output and durability. The textured sandy finish boosts spin, while the ShockOut anti-vibration system and Dual Pro Grip ensure comfort during high-intensity play. Designed for elite performance, the ST4 is your weapon for total court domination.