Unicorn watches were originally made by Rolex Watch Co and marketed as an independent line, primarily to Australia. The Unicorn name was patented March 17th 1919, Rolex used it until circa 1933. During this time they were fitted with Rolex movements. Later Unicorn watches were a brand of AS (Adoloph Schild) and were a seperate entitiy from Rolex. They used A Schild movements and depending on beat rate, were AS caliber 1711 (if 18000 A/h) or AS caliber 1901 (if 21600 A/h). Any thing marked with Incabloc is definitely NOT by Rolex The Incabloc shock protection system is the trade name for a spring-loaded mounting system for the jewel bearings that support the balance wheel in a mechanical watch, to protect the wheel's delicate pivots from damage in the event of physical shock, such as if the watch is dropped. It was invented in 1934 by Swiss engineers Georges Braunschweig and Fritz Marti Unfortunately, a Unicorn made after 1934/5 is not a Rolex product. I continually see Unicorn watches advertised for sale here faulsely claiming to be by Rolex . Rolex will confirm that this unicorn head logo has no connection to the Rolex company.