Portable interferential (IF-4000) dual channel therapy unit features include – 1. Dual channel. 2. Manual selection for 2 or 4 pads. 3. Adjustable pulse amplitude, interference frequency and difference frequency parameters. 4. 4 stimulation modes (frequency shifts): Continuous, 1/1, 8/8 and 10/10 ramped. 5. Includes 120V AC line cord adapter. 6. Comes with carrying case. 7. Unit in factory sealed box. 8. Unit comes case, leads, electrodes, AC adapter, 9V battery & manual. 9. Less than 1 lb. - light weight and easy to use.