In order to adapt to the high-intensity confrontation brought by the statement loopdrive balls in the era of new material balls, 729 "Stormwind 50" series high elasticity, high toughness and high density sponge have been specially developed. The sponge has surging hitting power and retains a clear and concentrated hitting feels. Combined with high tension long-lasting tackiness rubber topsheet, it can play strong rotation, forward impact and aggressive loopdrive balls in near table fast attack and medium far table statement.