Introduction
Thank you for choosing the Monster MH22156 Wireless Bluetooth 5.4 Earbuds. These earbuds are designed to provide a superior audio experience with advanced features such as Bluetooth 5.4 connectivity, a 16mm large sound unit with a composite titanium metal diaphragm for pure HiFi sound, and AI intelligent call noise reduction for clear communication. The ergonomic ear-hanging design ensures comfortable and stable wear, while IPX5 waterproofing makes them suitable for daily use and sports. Enjoy ultra-long battery life and seamless switching between music and game modes.

Monster MH22156 Wireless Earbuds in their charging case.
Package Contents
Please check the box for the following items:
- OWS Earphones (1 pair)
- Charging Case (1)
- Instruction Manual (1)
- Certificate of Conformity (1)
- Type-C Charging Cable (1)

Visual representation of the package contents.
Specifications
| Feature | Specification |
|---|---|
| Brand Name | MONSTER |
| Model | Monster Open Free AC100 |
| Communication | True wireless |
| Wireless Type | Bluetooth |
| Bluetooth Version | V5.4 |
| Bluetooth Transmission Distance | >10 meters (10m-20m) |
| Vocalism Principle | Dynamic |
| Sound Isolating | Yes |
| Active Noise-Cancellation | Yes (AI Intelligent Call Noise Reduction) |
| With Microphone | Yes |
| Waterproof Rating | IPX5 |
| Frequency Response Range | 20 - 20000Hz |
| Impedance Range | up to 32 Ω |
| Rated Power | 5MW |
| Earphone Battery Capacity | 50mAh |
| Charging Case Battery Capacity | 300mAh |
| Playing Time | About 6 hours |
| Talk Time | About 4 hours |
| Standby Time | About 30 hours |
| Charging Case Charging Time | About 1.5 hours |
| Charging Method | Charging case |
| Connectors | Type C |
| Material | Plastic, Silica Gel |
| Earphone Net Weight | 10g (each) |
| Charging Case Net Weight | 40g |
| Charging Case Size | 82*70*27mm |

Detailed product specifications.
Setup
1. Charging the Earbuds and Case
Before first use, fully charge the earbuds and the charging case.
- Connect the Type-C charging cable to the charging case and a power source.
- The charging case takes approximately 1.5 hours to fully charge.
- Place the earbuds into the charging case to charge them.

Battery life and charging overview.
2. Bluetooth Pairing
To pair your Monster MH22156 earbuds with your device:
- Ensure the earbuds are charged and powered on (White light on).
- Open the charging case. The earbuds will automatically enter pairing mode (Red and white lights flashing).
- On your device (smartphone, tablet, etc.), go to Bluetooth settings and search for available devices.
- Select "Monster Open Free AC100" from the list.
- Once connected, the earbud lights will turn off (No light on).
For TWS (True Wireless Stereo) pairing between the two earbuds, they should automatically connect when taken out of the case. If not, ensure both are powered on and follow the pairing steps.

Light status descriptions for various earbud states.
Operating Instructions
Touch Controls
The Monster MH22156 earbuds feature sensitive touch controls on each earbud:
- Tap once (Left/Right Ear): Answer/End Call, Play/Pause music.
- Tap twice (Right Ear): Volume Up.
- Tap twice (Left Ear): Volume Down.
- Tap three times (Right Ear): Next Song.
- Tap three times (Left Ear): Previous Song.
- Long press for two seconds (Left/Right Ear): Wake up Voice Assistant, Reject Incoming Call.

Detailed touch control functions.
Dual Mode (Music/Game)
The earbuds support a dual mode for optimized audio experience. Switch between Music mode for rich sound quality and Game mode for reduced latency, enhancing your gaming experience. The method to switch modes is typically via a specific touch gesture (refer to the full manual if available, or experiment with long presses/multiple taps if not explicitly stated).

Experience optimized audio with music/game dual mode.
AI Intelligent Call Noise Reduction
The earbuds feature an intelligent noise reduction algorithm that effectively minimizes ambient noise during calls, ensuring your voice is heard clearly. This feature is automatically active during phone calls.

AI intelligent call noise reduction in action.
Maintenance
To ensure the longevity and optimal performance of your Monster MH22156 earbuds:
- Cleaning: Regularly clean the earbuds and charging case with a soft, dry, lint-free cloth. Avoid using abrasive materials or harsh chemicals.
- Water Resistance: The earbuds are IPX5 waterproof, meaning they are resistant to splashes and sweat. Do not submerge them in water or expose them to heavy rain. Ensure they are dry before placing them back in the charging case.
- Storage: Store the earbuds in their charging case when not in use to protect them and keep them charged. Avoid extreme temperatures.
- Charging: Use only the provided Type-C charging cable or a certified equivalent.

IPX5 waterproof for daily use and sealed design.
Troubleshooting
If you encounter any issues with your earbuds, please refer to the following common solutions:
- Earbuds not pairing/connecting:
- Ensure both earbuds are charged and powered on.
- Turn off Bluetooth on your device and turn it back on.
- Forget "Monster Open Free AC100" from your device's Bluetooth list and attempt to pair again.
- Place earbuds back in the case, close the lid, wait a few seconds, then open to re-initiate pairing mode.
- Refer to the "Light Status Description" table for pairing mode indicators (Red and white lights flashing).
- No sound from one or both earbuds:
- Check the volume level on your connected device and on the earbuds.
- Ensure the earbuds are properly seated in your ears.
- Reconnect the earbuds to your device.
- Earbuds not charging:
- Ensure the charging cable is securely connected to both the case and the power source.
- Check if the charging case has power.
- Ensure the earbuds are correctly placed in the charging case.
- Clean the charging contacts on both the earbuds and the case with a dry cotton swab.
- Poor call quality:
- Ensure the earbuds are fully charged.
- Check for any obstructions between the earbuds and your device.
- Move to an area with less environmental noise to allow the AI noise reduction to function optimally.
User Tips
Maximize your experience with these helpful tips:
- Optimal Fit: Experiment with the ear-hanging design to find the most comfortable and secure fit for your ears. A good fit enhances sound quality and stability, especially during exercise.
- Regular Charging: For uninterrupted use, make it a habit to place your earbuds back in their charging case when not in use. This ensures they are always ready for your next listening session.
- Utilize AI Noise Reduction: When making calls in noisy environments, trust the AI intelligent call noise reduction to keep your conversations clear.
- Switch Modes: Don't forget to switch to Game mode when playing mobile games for a more immersive experience with reduced audio latency.
- Stay Dry: While IPX5 waterproof, always wipe down your earbuds after a workout or exposure to moisture to prevent long-term damage.
Demonstration of the Monster MH22156 earbuds and charging case.
Warranty and Support
Your Monster MH22156 Wireless Earbuds come with a standard manufacturer's warranty. For detailed warranty information, please refer to the documentation included in your package or contact the seller directly.
For technical support, troubleshooting assistance beyond this manual, or warranty claims, please contact the Monster Audio Store customer service.