What is EMS technology?Electrical muscle stimulation (EMS), also known as neuromuscular electrical stimulation, uses electrical impulse to induce muitiple muscle contractions. The central nervous system contracts muscles; EMS has been proved to be an active muscle strengthening tool.What is the purpose of EMS?• Muscle strengthening• Relieve soreness• Prevent wasting muscle atrophy • Relax one's muscles• Muscle relaxation• Beauty conditioningProduct Parameters:Product size: 15*6.5CMSize of controller: 6*2*8CMWeight of controller: 28.4gBattery capacity: 200MAhAdjusting gear: 8 modes, 19 levels strength.Charging time: 1HWorking time: 60 minutes