Like the first attempt at forging an alliance with Pentax, Zeiss designed a new common lens mount, known as Contax/Yashica mount (C/Y) to be used on cameras bearing both marques. The first model, the Contax RTS (short for "Real Time System"), was designed by Prof. Dr. Katsuiko Sugaya, styled by the Porsche Design studio, and manufactured by Yashica as Top Secret Project 130 in 1974.