Heat Muscle Massager is a modality that has been used since the 1940s. Heat Massager is applied using the head probe that is placed in direct contact with your skin via a transmission coupling gel. Heat Muscle Massager has been shown to cause increases in: healing rates tissue relaxation tissue heating local blood flow scar tissue breakdown. Technical Specifications - Frequency : 1 MHz, Output : 15 Acoustic, Head : 3.0 watts/cm2 Treatment Time : 0-30 Min Modes: continuous and pulse waves. Available voltage: 110v/220v Main Unit : 01 Qty. Applicator :01 Qty. Power Cord :01 Qty Instruction Manual :01 No