1.This product have two working systems.(need two arry plates, service for two person)in fact, you can get double benifit from it.At the same time, 2.It has record function (can record working the number of times) 3.Download music function.(you can lisiten music whatever you like to relax your heart). This unit comes with: 1.Two arrays that create (pos.& neg.Ions) 2.Cuffs for testing if treatment is working 3.Headphones for listening to mp3s 4.USB cable for transferring mp3s to unit 5.Electrical 110V/220V plug 6.Instruction manual Function: Net weight:3.4kg Gross weight:5.1kg Packing dimension:45cm * 42cm * 15cm (L*W*H) Product dimension:40cm * 23cm * 11cm (L*W*H) Voltage:110V/220V rated power:50W Current:0.5-2.5A Packing term:Colour paper box