pf777Aktisil® PF 777 by Hoffmann Mineral acts as a functional filler. It is an activated Sillitin® Z 86, produced by modifying the surface with an alkyl functional group.Debuting at Watches & Wonders Geneva 2022. Starting with the Tonda PF form factor that we're getting to know extremely well around these parts, the Tonda PF Skeleton strips away the dial to reveal the PF777 caliber