1.we are manufacturer 2.material is ZrO2 3.ceramic bearing 4.Prompt delivery time 5.Competitive price ZrO2:Usage:high precision,vacuum, high temp,low temp,electric insulation,high precision ballscrew set,valve balls for acid,alkali,salt,measure pumps,flowmeter and valve ball plunger for deep well pump. Characterisitic: resistance to strong acid,strong alkali,salt and gas of deleterious,long life, ...