2 Pcs HRA90 Nano Ceramic Swivel Knife Blade leather Craft Fillgree Tool Kit Set Material: Nano-Ceramic Flat Head Nano-Ceramic Blade Width: 3/8" (10mm) Oblique Head Nano-Ceramic Blade Width: 1/4" (7mm) More information about Nano-Ceramic Blade: Ceramic cutting tools have high hardness HRA90, wear a metal knife 60 times, second only to the world's hardest substance--Diamond (HRA100), and general metal cutting tool hardness is between HRC45 to HRC58). So long as the use does not fall to the ground without external impact, not to chop or cut, under normal use do not require sharpening permanent. Package including: 1pc Flat Head Nano-Ceramic Blade, 1pc Oblique Head Nano-Ceramic Blade.