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Swatch Sistem51 Specifications
| Reference | SO27B100, SO27E100, SO27M100 |
|---|---|
| Case Size | 42mm |
| Lug Width | 20mm |
| Lug-to-Lug | 47mm |
| Thickness | 14.3mm |
| Case Material | plastic (ASUV) |
| Crystal | plastic (PMMA) |
| Water Resistance | 30m |
| Movement | Sistem51 (SIV automatic) (automatic) |
| Bezel | fixed smooth bezel |
| Crown | push-pull |
| Case Back | display caseback (plastic) |
| Price Range | $150-$200 |
Compatible Straps for the Swatch Sistem51
The Sistem51 uses a 20mm Lug Width and is compatible with the following strap types.
| Type | Recommended Brand | Why It Works | Price Range | Link |
|---|---|---|---|---|
| NATO/ZULU | Swatch OEM | Classic look, easy to swap, fits 20mm lugs | $15–$80 | |
| rubber/silicone | Barton | Water-resistant, comfortable for daily wear | $15–$80 | |
| leather | Archer | Dresses up the watch, fits 20mm lugs | $15–$80 | |
| perlon | Swatch OEM | Lightweight, breathable, adjustable fit | $15–$80 | |
| canvas | Swatch OEM | Casual, durable field-watch aesthetic | $15–$80 |
Replacement Parts for the Swatch Sistem51
| Part | Description | Compatibility Note |
|---|---|---|
| crystal (plastic) | Protective cover over the dial | Fits 42mm case |
| spring bars | Pins that hold the strap to the case | 20mm, 1.5mm diameter recommended |
Modding the Swatch Sistem51
The Sistem51 is a popular platform for modding. Here are the most common modifications.
- strap swap — Upgrade to a premium aftermarket strap or metal bracelet.
Frequently Asked Questions
What lug width is the Swatch Sistem51?
The Sistem51 has a 20mm lug width.
What makes the Sistem51 special?
The Sistem51 is the world's first fully mechanical automatic movement assembled entirely by machine. It uses only 51 components and a single screw, making it one of the most innovative mechanical movements ever produced. The movement is hermetically sealed and not designed for servicing.
Can the Sistem51 be serviced?
No. The Sistem51 movement is hermetically sealed with no user-serviceable parts. If the movement fails, the entire module is replaced rather than repaired. Swatch designed it this way to keep costs low.