This model exists in two numbered series, produced in yellow gold and in white gold.The reference to the Apollo 11 mission and the date of production of the first pieces (1980) indicate that this series may have been produced to commemorate 10 years since the Apollo 11 moon landing, although there is no indication of the anniversary.The yellow gold version, estimated at 300 pieces, was delivered approximately from 1980 to 1988 (half in 1980 and intended exclusively for the German market). It appears that just a dozen examples mounted a leather strap.