MB&F
MB&F Horological Machine N°4 HM4 Thunderbolt 40.TSL.B
The MB&F Horological Machine N°4 HM4 Thunderbolt (reference 40.TSL.B) is a watch.
Specifications
Case
- Reference
- 40.TSL.B
- Collection
- Horological Machine
Dial versions
This reference was made with these dials and finishes.
40.TSL.B
How it compares within the Horological Machine family
Side by side with other references in the same collection, from the catalog.
| Reference | Size | Material | Dial | Caliber | Years |
|---|---|---|---|---|---|
| 40.TSL.B (This watch) | — | — | — | — | — |
| 10.T41RL.R | — | — | — | — | — |
| 20.DCRTL.B | — | — | — | — | — |
| 20.DWWTL.R | — | — | — | — | — |
| 34.BTL.B | — | — | — | — | — |
| 56.STDL.B | — | — | — | — | — |
| 90.RL.AB | — | — | — | — | — |
| 91.SRL.BU | — | — | — | — | — |
| 91.SWL.RG | — | — | — | — | — |
About the Horological Machine family
The Horological Machines are MB&F's founding collection, starting with HM1 in 2007. Each is a three-dimensional sculpture with a distinct theme, from spacecraft and jet engines to frogs, racing cars and a bulldog, and they often display the time in unusual ways, such as on rotating cones or through prisms.
The catalog includes many references across the series, in titanium, gold and other materials, each usually made in a limited run of a given material and colour. Buyers expect the full set and elaborate box, the edition number and a service history from MB&F, and every display should be checked for correct function.
Catalog facts checked October 2026.