Reference library
Reference library — 4 pages covering topics.
- Case Size vs Lug-to
- How to Read a Watch Reference Number
- Service Intervals by Brand: What Makers Publish
- Water Resistance Ratings Explained
Plain-language reference guides for people buying and owning a luxury watch. Each guide below explains one topic in detail, using published figures and verified specifications, so you can check a claim before you rely on it. They sit alongside the live inventory and the buying guides on this site.
- Case Size vs Lug-to-Lug — Case diameter and lug-to-lug measure different axes. See why a 38mm watch can span 47mm, plus verified figures for the Reverso, Turtle and Journe Élégante.
- How to Read a Watch Reference Number — Decode Rolex, Patek Philippe and Audemars Piguet reference numbers block by block: metal codes, bezel digits, dial iterations and generational updates.
- Service Intervals by Brand: What Makers Publish — What Rolex, Omega, Patek Philippe, Tudor, Seiko and Jaeger-LeCoultre actually publish about service intervals, and where third-party figures diverge from the maker.
- Water Resistance Ratings Explained — What a water resistance marking really means: ISO 22810 test procedures, why a depth figure is lab pressure, and how ISO 6425 diver's certification differs.