Our design team developed this tennis trainer so you can play tennis easily wherever you are! With its ballastable base tennis ball and elastic band the Tennis Trainer lets you and your children easily practise your tennis shots alone or enjoy playing together! Stability 1.5 ballastable base, remains stable even on strong hits. Ease of use Built-in storage areas for the ball & elastic. Easy to fill and empty. Ecodesign Base made of recycled plastic, which reduces its environmental impact. Durability String, knotted elastic band that won't get twisted. Our design team developed this tennis trainer so you can play tennis easily wherever you are!