Main features: Matte finished blade made of zirconium oxide (also called zirconium) Zirconium material keeping 85¡ã hardness just second to diamond which give the ceramic knife its outstanding sharpness and edge retention Customized company name or logo on blades and packing are welcome Certificates: EU testing, LFGB testing, PONY testing, SGS Corrosion-resistance knives advantage: Transfers no metallic taste or smell to food Has no acid and alkaline reaction with food Lifespan is 10 times longer than conventional steel knife Easy to clean up to prevent bacteria growth Ceramic knives maintenance: Only use plastic or wood cutting board As with only knife, avoid dropping, throwing or general misuse Avoid using the ceramic knife to cut seeds, bones, frozen food or other hard product A ceramic knife is not flexible, don't use it to smash garlic, open cans or attempt to bent it in any way Hand wash only Do not attempt to sharpen the ceramic knife yourself unless you have access to sharpener specific to ceramic knives Ceramic knives wear: Over time miniscule abrasions and chipping can be seen on the blade This is normal wear for the hard material of which the ceramic knife is made The knife will retain its sharpness despite tiny chipping. What in the box: 3"ceramic paring kmife, 4"fruit ceramic knife, 5"utility knife, 6"chef's knife, ceramci peeler Packed in black magnet box with color paper card 34pcs/ctn Gw:26.5kg.