5/pk5/pk Alpen FG #392.018 Coarse Grit, Interproximal Diamond Bur. Alpen Diamond Instruments are Swiss made providing enhanced quality. They undergo a unique, multi-layer bonding production process, which secures complete and uniform coverage, especially at the all-important tip. Alpen Diamond Instruments are manufactured under ISO standards. The multi-layer, natural diamond application process provides maximum uniform crystal coverage for enhanced cutting and longevity. Reusable.