MULTIS HYDRO MJ842 rotates at a high speed and is structured to be used for the equipment which transfers air and coolant, both fluids. Oil Mist, provided through the air port, lubricates the seal face and bearings, thus guarantees the longevity even for high-speed work. The Coolant port is Cracking-Type structured to be also used in Dry-Running and its structure of sealing. It is especially designed to prevent the permeation of the coolant to the air line in case of the leakage. Rotary joints, which move vertically by its equipment structure, guarantee the excellent work for its high-accuracy process.