Made between 1932 and 1936, the original Contax, known as Contax I after later models were introduced, was markedly different from the corresponding Leica. Using a die-cast alloy body it housed a vertically travelling metal focal-plane shutter reminiscent of the one used in Contessa-Nettel cameras, made out of interlocking blackened brass slats somewhat like a roll-up garage door. This complex shutter became the characteristic of the Contax camera and its Super-Nettel derivative. By contrast, the competitive Leica followed the established design of using rubberized fabric shutter curtains wound around rollers, moving horizontally. The Contax design allowed a higher maximum shutter speed: the top speed was 1/1000s, then increased to 1/1250s in the Contax II. The fact the shutter ran across the shorter dimension of the format area was a significant factor for achieving this technical feat. The interlocking slats were aligned by specially woven silk ribbons, which were very strong but subject to wear. Replacing these ribbons was difficult but, contrary to modern cameras, made for a 400,000-cycle life.