Derby Professional Blades #100Fits all straight RazorsSuitable for all cutthroat/shavette Type RazorsPerforated, hardened and ground by utilizing most advanced equipmentCutting edges are deposited with chromium ceramic, tungsten, and platinumDerby professional stainless steel single edge blades fit all straight/barber razors (cut throat razors)Suitable for all cut throat/shavette type razors including shaving factory, dovo, focus, parker