quattro[Moderator]
18092
Two racing Berthouds
Only 20 iterations of the Régulateur Squelette (RS) movement have been produced, and 2 of them have been dedicated exclusively to Singapore retailer Sincere Haute Horlogerie (SHH).
The Régulateur Squelette FB 1RS.6-4 & 6-5 feature a sandblasted stainless steel octagonal cases with DLC coating.
The racing aesthetic isn't for me at all, but it might be very appealing to you!
Best, Emmanuel
FB 1RS.6-5 (left) &
6-4 (right)

credit: @yohann_martinez & SHH