Since 1959, DHS T.T. ball has been official ball of world-class games which is widely welcomed over the world. From 38mm to 40mm, celluloid to various kinds of new material, DHS always takes the lead in the forefront of T.T. ball innovation. The SEAM, then the FOCUS, and the PRECISE. CELL-FREE & CELL-FREE-DUAL are 40+ plastic balls developed by DHS. Keeping the continuity of celluloid balls' characterstics on hitting sense, droppoint, sound, rotation and trajectory. CELL-FREE-DUAL ball adopts new material formula and craftsmanship different from CELL-FREE ball, to have more accurate sphericity and better elasticity.