1. Introduction and Overview
The Roscoe Medical Twin Stim OTC is a dual-function device combining Transcutaneous Electrical Nerve Stimulation (TENS) and Electrical Muscle Stimulation (EMS) therapies. TENS therapy is primarily used for pain management by stimulating nerves, while EMS therapy is used for muscle rehabilitation and strengthening by stimulating muscle contractions. This versatile unit offers both functionalities in a single, compact device.
The device is designed to provide custom clinical-strength pain relief and muscle rehabilitation, previously available by prescription and now accessible over-the-counter. It features dual channels, allowing up to four electrodes to be used simultaneously for broader treatment areas.
Video: Roscoe Medical TENS Unit and EMS Muscle Stimulator Overview. This video provides a general overview of the device and its capabilities.
2. What's Included
Your Roscoe Medical Twin Stim OTC package includes the following items:
- Dual Channel Digital TENS EMS Device
- 4 x 2"x2" Premium Electrodes
- User Manual
- 2 Lead Wires
- Hard Case Carrying Case
- 1 x 9V Battery (included)

Image: The complete Roscoe Medical Twin Stim OTC kit, including the device, electrode pads, lead wires, battery, and user manual, all stored within a protective hard carrying case.
3. Setup
- Battery Installation: Open the battery compartment on the back of the device. Insert the included 9V battery, ensuring correct polarity. Close the battery cover securely.
- Connect Lead Wires: Plug the lead wires into the output jacks located at the top of the device. The device has two channels (CH1 and CH2).
- Attach Electrodes: Connect the electrode pads to the pins on the lead wires. Ensure a secure connection.
- Prepare Skin: Clean and dry the skin area where electrodes will be placed. This helps ensure optimal adhesion and conductivity.
- Apply Electrodes: Remove the protective backing from the electrode pads and firmly place them on the skin. Ensure the pads are placed at least 2-6 inches apart on muscle, not directly over bones or joints.
Video: This video explains the difference between TENS and EMS functions and demonstrates the setup process, including connecting electrodes and applying them to the body.
4. Operating Instructions
The Twin Stim OTC unit features a user-friendly interface with a protective panel cover. Always ensure the device is turned off before attaching or detaching electrodes.
- Power On/Off: Turn the intensity dials (CH1 and CH2) clockwise until you hear a click to power on the device. Turn counter-clockwise until you hear a click to power off.
- Select Mode: Press the 'MODE' button to cycle through the available TENS and EMS programs. The device offers 5 TENS modes and 2 EMS modes. Consult the user manual or a healthcare professional to determine the most appropriate mode for your condition.
- Adjust Settings: Use the 'SET' button to navigate through adjustable parameters (e.g., pulse width, rate, ramp time). Use the up/down arrow buttons to increase or decrease the selected setting.
- Set Intensity: Slowly turn the intensity dials (CH1 and CH2) clockwise to increase the stimulation intensity. Start with a low intensity and gradually increase until you feel a comfortable, tingling sensation (for TENS) or a gentle muscle contraction (for EMS). Avoid setting the intensity too high, especially when first using the device.
- Set Timer: The treatment time is adjustable from 1 to 60 minutes. The device will automatically shut off once the set time has elapsed.

Image: Detailed view of the device's control panel, highlighting the LCD screen, mode and set buttons, and intensity dials.
Video: This video demonstrates the basic operation of the Roscoe TENS and EMS unit, including turning it on, selecting modes, and adjusting intensity.
5. Care and Maintenance
- Cleaning Electrodes: After each use, gently wipe the adhesive side of the electrode pads with a damp cloth or a small amount of rubbing alcohol to remove any skin oils or debris. Allow them to air dry completely before reattaching the protective film.
- Storing Electrodes: Store the electrode pads on their original plastic backing or a clean, smooth surface. Keep them in a sealed bag to prevent drying out and prolong their lifespan.
- Device Cleaning: Wipe the device with a soft, dry cloth. Do not use abrasive cleaners or immerse the device in water.
- Battery Replacement: Replace the 9V battery when the low battery indicator appears on the display or when the device no longer powers on.
6. Troubleshooting
- No Stimulation: Ensure the device is powered on, the battery is correctly installed, and the lead wires are securely connected to both the device and the electrodes. Verify that at least two electrodes are properly applied to the skin.
- Weak or Uneven Stimulation: Check electrode placement and ensure good skin contact. Clean the electrodes and skin area. Replace old or worn-out electrodes. Increase the intensity gradually.
- Skin Irritation: Ensure electrodes are clean and properly applied. Avoid placing electrodes over broken or irritated skin. If irritation persists, discontinue use and consult a healthcare professional.
- Device Not Responding: Replace the battery. If the issue persists, contact customer support.
- No Pain Relief/Muscle Rehabilitation: Ensure correct mode and settings are selected for your specific condition. Proper electrode placement is crucial. If you are not experiencing desired results, consult a healthcare professional for guidance on optimal settings and placement.
7. Specifications
| Product Dimensions | 9 x 2.1 x 7.7 inches |
| Item Model Number | DS2202-OTC |
| Weight | 13.44 ounces |
| Batteries | 1 x 9V battery (included) |
| Manufacturer | Compass Health Brands |
8. Warranty and Support
The Roscoe Medical Twin Stim OTC device comes with a 1-Year Warranty, ensuring quality and reliability. For any questions, technical assistance, or warranty claims, please contact Roscoe Medical's USA Support Staff.


9. Important Safety Information
To ensure safe and effective use of your TENS/EMS device, please adhere to the following guidelines:
- Consult a Professional: Always consult with a healthcare professional (e.g., doctor, physical therapist) to determine the most appropriate treatment mode, settings, and electrode placement for your specific condition.
- Electrode Placement:
- DO NOT place electrodes on your head, face, neck, or throat.
- DO NOT place electrodes over your heart or across your chest.
- DO NOT place electrodes over open wounds, rashes, or irritated skin.
- Ensure at least two electrodes are always connected to the skin for the device to function properly.
- Device Operation:
- Always turn off the device before applying, removing, or repositioning electrodes to avoid sudden shocks.
- Start with the lowest intensity setting and gradually increase it to a comfortable level. Avoid excessively high intensity.
- Do not use the device while sleeping, driving, operating machinery, or during any activity where involuntary muscle contractions could be dangerous.
- Medical Conditions: If you have a pacemaker, heart condition, epilepsy, or are pregnant, consult your doctor before using this device.
- Not a Substitute for Medication: This device is intended for pain relief and muscle stimulation, not as a substitute for prescribed medication or professional medical treatment.





