How to read the inscription
In an inscription such as RB2242 ··· 50□·· ···, each part has a purpose:
This reference comes in 2 sizes. Find the number right before the □ symbol on your arm and choose that same lens size:
- 50□ → 50 mm
- 53□ → 53 mm
The number after the □ is the bridge: it isn't used to choose the lens. Can't read it? Measure your lens from side to side at its widest point; that measurement in millimeters matches the lens size.
