What does “LB” mean?

LB is the Rolex reference suffix for a blue bezel, from the French 'lunette bleue'. It is seen mostly on precious-metal and two-tone Submariner Date models, for example the white gold 116619LB 'Smurf' and 126619LB 'Cookie Monster', the yellow gold 116618LB, and the steel and yellow gold 116613LB and 126613LB, known as the 'Bluesy'.

Because the LB suffix only says the bezel is blue, the dial can differ: the Smurf and Bluesy have blue dials, while the Cookie Monster has a black dial. Dealers therefore state both the reference and the dial colour in listings. Other Rolex models with blue bezels may use different suffixes or none at all, so check the full reference rather than assuming from the letters. Since LB models are gold or part gold, they are heavier than steel and show scratches more readily, which is worth keeping in mind when grading condition.

Example: '126613LB, blue dial, blue bezel, 2022, full set.'