Sennheiser's world of headphones is actually 70 years of chasing the white rabbit. The story of headsets bearing this logo - the name of the brand's founder - started for good in 1968, when the world's first open-back headphones, HD 414, revolutionized the market. By the end of 1969, over a hundred thousand pairs of them were sold, and more than ten million unto this day. The introduction of unipolar electrostatic headphones in 1977 was the next milestone for the German engineers. I am speaking about the 2000 model, which in some ways was the ancestor of one of the best headsets in the world - the Orpheus HE 90/HEV 90 electrostatic headphones, presented in 1991. As regards the equipment for home and personal use, the company has focused on designer Momentum series and lifestyle Urbanite headphones, introducing new wireless and in-ear products from time to time.