The string that makes the difference Would you like more? The Polyfibre Black Venom ties up an extra packet of Spin! Polyfibre consulted the Spin doctor himself for Black Venom. His prescription for more swirl? A mechanically incorporated device which reaches deep into the felt ball. With the Black Venom you will send curves that drive your opponent right off the court. The new Molecular structure (SMD) assures more comfort and control. Prevents swivel: Get yourself Polyfibre Black Venom Highlights: Durable stringing for ambitious players. enormous Spin potential! for a powerful and temperamental game Snap-Back-Effect prevents the strings from slipping. Strings of Olefin- Polymer with Corona coating.