← All references
· Explorer I
Explorer I Reference 6610
"Pre-1016"
Refinement of the 6350, with a cleaner case and improved movement. The 6610 bridges the earliest Explorer design language and the landmark Ref. 1016 that followed. Late examples received tritium lume as radioactive radium was phased out. Some examples show applied (3D) rather than printed dial markers — an important transition toward the definitive Explorer aesthetic.
Notable: Transitional reference; late examples are nearly identical to early 1016s.
Technical Specification
| Reference | 6610 |
| Production years | 1955–1959 |
| Case diameter | 36 mm |
| Case material | Oyster steel |
| Movement | Cal. 1030 → Cal. 1530 |
| Jewels | 17 |
| Frequency | 18,000 bph |
| Power reserve | 38h |
| Crystal | Acrylic (plexiglass) |
| Water resistance | 100m |
| Bracelet | Riveted Oyster / flat-link Jubilee |
| Lume | Radium → Tritium (late production) |
| Dial colour | Matte black |
| Numerals | 3–6–9 Arabic, applied white metal |
| Hands | Mercedes hour hand, baton minute, slim seconds |
| Crown | Twinlock screwed-down crown |
| Serial range | 14xxxxx – 20xxxxx |
Variants & Production Marks
Matte black, printed markers
Applied white metal indices (late)