Switzerland’s largest glass group, holding 28 live VKF recognitions for fire-rated glazing — 15 vertical glazing approvals and 13 glazed fire doorsets — across its Bützberg head office and its FIRESWISS branch at Buochs, which is the group’s dedicated fire-glass plant. Its VKF numbers run from the 125xx series to the 20xxx series, the longest continuously maintained fire-glazing holding in the register.