The ES-320 is designed so practitioners can check whether the patient has used the unit as prescribed (PAT. P), or allows you to check the patient's usage, helping you make reliable evaluations on therapeutic effect based on the parameters specially set up for the patient. Blow-out (ejector) vacuum system: No water reservoir is needed. It is virtually maintenance-free, since dust or moisture does not adhere inside the tube or on the connections, resulting in preventing blockages and oxidation. Reusable sponge disks or disposable paper disks can be used in the vacuum electrode. Two vacuum units can be used with our 4-channel electrotherapy unit at the same time, enabling two independent 4-pole IF or four independent 2-pole IF or other modes to be used simultaneously or one vacuum unit with our 2-channel electrotherapy unit. Connectable to the EU-940, the ES-520 or the ES-521 electrotherapy unit