It comes uniquely equipped with a soundhead pre-warming feature on an ergonomically designed sound head for increased patient comfort.Before starting therapy the soundhead preheats so that it's more comfortable and warm.Once therapy is engaged,the pre-warming feature turns off to allow for the most effective treatment. With three output intensities,and three treatment time selections,the aluminum sound head is watertight for use in underwater therapy (for 30 minutes),though only the metal portion is watertight - you can not submerge the entire sound headThis unit is very similar to used in your Chiropractor's or Physical Therapist's office.Very effective in pain relieve Application: Relieve Pain Reduce inflammation fast perfect for reducing tissue Sports injuries - Neck & shoulder pains, ankle injuries, groin injuries hamstring strains... Sciatica pain, arthritis pains, joint pain, muscle pain Soft tissues injuries recovery Cellulite reduction Item Name: Ultrasound Physiotherapy Device Rated Vol:100-240V, 50/60Hz, 600mA Frequency: 1MHz Timer:3 Levels (5min/10min/15min) Effective Radiation Area:4cm Effective Ultrasound Wave:3.0W/cm Pulse repetition rate:100Hz10% Duty cycle:Low 30% - Medium 40% - High 50% Colour:White Material:Plastic Package Contents:1 * joint massager