The reference 5100 is a landmark model for a number of reasons. Launched in 1970, it was Rolex's first reference fitted with a quartz movement. Rolex first produced 1000 units to test the ‘Beta 21’, and all examples were sold out before the watch even hit the market. The 'Beta 21' was also Rolex's first reference to feature a sapphire crystal and quick set date function – two key innovations and components that are used in Rolex's current line of production.

Ref Variations: 5100-8, 5100-9, 5100-2,