BIRKENSTOCK. 126163. RIO. EVA. NEON PINK. The BIRKENSTOCK Rio model is a classic kids shoe. Designed back in the 1970s it has been a laid-back summer companion for generations of children ever since. BIRKENSTOCK has reinterpreted the Rio sandal in stylish neon colors and high-quality synthetic material. Modeled on the cork sandal it is made from the ultra lightweight and highly flexible synthetic material EVA.