Specifiction: Type: Knee Heat Massager Size: 25*23.5*8.5cm Color: Black Voltage/Power: Voltage: 7.4V, Rated power: 12W, Charger: Voltage 8.4V, Current 1.2A Battery: 6000MAH ,can be used for 4-8 hour after charge fully Plug Type: UK/EU/US Plug for option Body Area: Knee, Joint Massage Function: Physiotherapy Therapy, Heat Therapy Weight: 1 kg (Approx.) Focus on: Bone stinging, Joint swelling, Leg weakness, Rheumatoid arthralgia, Numbness stiff, Arthritis... Description: Warm deep into knee joint, the heat deteminer surround knee design. Low intensity, no harm to your knees, comfortable to massage. High-frequency and low intensity massage, active your knee joints and muscles. 1) Relieve arthritis pain and soreness in joints 2) Reduce inflammation and swelling 3) Improve blood circulation and metabolism 4) Promote regeneration and wound healing 5) Relax muscles and stop or prevent spasm