The Professional Blade Zirconium oxide blades of the knives given free with the Hurom extractor are particularly pure and do not contain metal ions, do not oxidize the cut products and do not transmit the taste of steel to food; they are impervious to the attack of acids, oils and salts, and therefore never rust. Vegetables and fruit cut with ceramic blades DOES NOT oxidize and is the perfect combination with Hurom extractors. Italjuicer Hurom distributor for Italy provides warranty and assistance only for products purchased from authorized retailers which, in addition to being supplied with a manual and recipe book in Italian, are certified and tested for the Italian market. Products purchased from unauthorized resellers may come from abroad and therefore not be suitable or have operating problems, in which case we will not be able to provide assistance or manuals. Please protect yourself from any problems by purchasing Hurom products only from authorized resellers.