NETBURNER BALLISTIC â„¢ FF 2 is recommended for track sports such as volleyball and basketball. This model develops GEL-NETBURNER â„¢ products even further with advanced components that promote a more flexible fit and better durability. This shoe is designed with grooves made of polyurethane rubber over the toe for increased protection and durability, while improving the flexibility of the front foot. The supporting inner heel construction helps to give a firm and stable feeling to inspire safety in sharp jumps on the pitch. is injected with FLYTEFOAM â„¢ Propeller technology in the midsole and provides a failing response with cushioning under the foot. Designed to improve stability, the integration of TWISTRUSS større technology also provides greater mobility and speed at fast twists and turns. Equipped with deeper flex grooves in the outsole to increase grip on the court, the NETBURNER BALLISTIC â„¢ FF 2 volleyball shoe provides you with technology that improves flexibility and durability.