Seiko Alpinist SPB121 vs Seiko Prospex Monster (4th Generation, SRPD27) SRPD27K1
Specifications
Marked rows differ| Case | ||
| Case diameter | 39.5 mm | 42.4 mm |
|---|---|---|
| Thickness | — | 13.4 mm |
| Lug-to-lug | — | 47.5 mm |
| Water resistance | 200 m | 200 m |
| Movement | ||
| Movement | automatic | Mechanical automatic (self-winding, with manual winding and hacking) |
| Caliber | 6R35 | 4R36 |
| Price | ||
| Launch MSRP | $725 | $495 |
| Details | ||
| Bezel | — | Unidirectional rotating, 120-click |
| Case material | — | Stainless steel |
| Crown | — | Screw-down |
| Crystal | sapphire | Hardlex mineral crystal (with cyclops lens over the date) |
| Day date | — | true |
| Dial color | — | Black |
| Frequency vph | — | 21600 |
| Jewels | — | 24 |
| Lume | Lumibrite | LumiBrite on hands and indices |
| Power reserve hours | — | 41 |
| Strap | — | Black silicone strap |
Sources
Verified · 5 referencesEvery spec on this page was independently checked against the sources below before publishing.