Like the other tourbillon movements used by Bell & Ross, the BR-CAL.380 was developed by MHC Manufacture Haute Complication, a Geneva-based complications specialist formed by watchmakers from BNB Concept, a movement maker that was acquired by Hublot after going bust. Amongst other things, MHC helped build the Girard-Perregaux Tri-Axial Tourbillon.
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