The 1T training ball from Schildkröt has been a very popular, training ball for school sports and initial training or for leisure games when larger quantities are required for decades. This new variant of the 1T, the 1T Poly 40 , is now celluloid-free. Today plastic balls have absolutely comparable playing properties and an identical quality and durability. However, they are much more environmentally friendly in production, which is why the changeover was initiated by the ITTF.