1. Introduction
Welcome to your new Monster Open Ear AC210 Headphones. This manual provides detailed instructions for setting up, operating, and maintaining your headphones to ensure optimal performance and longevity. Please read this manual thoroughly before using the product.
1.1 Package Contents
Verify that all items listed below are present in your package.
- Monster Open Ear AC210 Headphones (Left & Right)
- Charging Case
- USB-C Charging Cable
- Quick Guide

Image: The package contents including the headphones, charging case, USB-C cable, and quick guide.
2. Product Overview
The Monster Open Ear AC210 Headphones feature an open-ear design for comfort and situational awareness, equipped with Bluetooth 5.4 for stable connectivity.

Image: The Monster Open Ear AC210 Headphones and their charging case.
2.1 Key Features
- Open Ear Design: Allows you to hear your surroundings while enjoying audio.
- Flexible Earhook: Provides a secure and comfortable fit.
- Lightweight: Each earbud weighs approximately 5 grams for extended wear comfort.
- Bluetooth 5.4: Ensures a stable and efficient wireless connection.
- Dual 12mm Drivers: Delivers clear stereo sound.
- Extended Playback: Up to 30 hours of total playback with the charging case.
- Touch Control: Intuitive controls for music and calls.
- IPX5 Water Resistance: Resistant to sweat and light splashes.

Image: A woman wearing the Monster Open Ear AC210 Headphones, illustrating the open ear design, flexible earhook, and lightweight nature.

Image: A diagram illustrating the 12mm ultra-large driver and diaphragm responsible for the stereo sound effect.
3. Setup
3.1 Charging the Headphones and Case
Before first use, fully charge the headphones and the charging case.
- Place the headphones into the charging case, ensuring they are correctly seated.
- Connect the USB-C charging cable to the charging port on the case and to a power source (e.g., USB wall adapter, computer USB port).
- The indicator lights on the case and/or headphones will show charging status. Refer to the Quick Guide for specific light indicators.
- A full charge provides approximately 6 hours of playback for the headphones, with the charging case extending total playback to about 30 hours.

Image: The Monster Open Ear AC210 Headphones inside their charging case, illustrating the 400mAh battery capacity of the case and the total 30 hours of playback time.

Image: A visual representation of the battery life, indicating 6 hours of playback on a single charge and up to 30 hours with the charging case.
3.2 Bluetooth Pairing
Follow these steps to pair your headphones with a Bluetooth-enabled device.
- Open the charging case. The headphones will automatically enter pairing mode.
- On your device (smartphone, tablet, etc.), go to Bluetooth settings and ensure Bluetooth is enabled.
- Search for available devices. Select "Monster Open Ear AC210" from the list.
- Once connected, you will hear an audio prompt, and the indicator lights on the headphones will change.
- The headphones support one-step pairing and will automatically reconnect to the last paired device when removed from the case.

Image: A smartphone screen displaying the Bluetooth settings, with "Monster Open Ear AC210" shown as a connected device, demonstrating the one-step pairing process.
4. Operating Instructions
4.1 Wearing the Headphones
For optimal comfort and sound quality, ensure the headphones are worn correctly.
- Pick up the headphones from the charging case.
- Place the earhook over your ears.
- Rotate the headphone upward along the auricle to the appropriate position.
- Ensure the earbud is fully inserted and feels secure.

Image: A four-step diagram illustrating the correct method for wearing the open ear headphones, from picking them up to fully inserting them.
4.2 Touch Controls
The headphones feature intuitive touch controls on each earbud.
| Action | Function (Left/Right Earbud) |
|---|---|
| Click x 2 | Answer Call / Play/Pause Music |
| Hold x 2s | Reject Call |
| Click x 3 (Left) | Previous Song |
| Click x 3 (Right) | Next Song |
| Click x 1 (Left) | Volume Down |
| Click x 1 (Right) | Volume Up |

Image: A visual guide to the smart touch controls on the Monster Open Ear AC210 Headphones, detailing actions for calls, music playback, and volume adjustment.
5. Maintenance
5.1 Cleaning
- Wipe the headphones and charging case with a soft, dry, lint-free cloth.
- Do not use abrasive cleaners, solvents, or aerosol sprays.
- Ensure charging contacts are clean and dry before placing headphones in the case.
5.2 Storage
- Store the headphones in their charging case when not in use to protect them and keep them charged.
- Avoid storing in extreme temperatures or high humidity.
5.3 Water Resistance
The Monster Open Ear AC210 Headphones are rated IPX5 water resistant, meaning they can withstand sweat and light splashes of water. They are not designed for submersion in water or exposure to pressurized water jets. Ensure the headphones are dry before charging.

Image: A visual representation of the headphones being splashed with water, demonstrating their water-resistant capabilities. Note: Product is rated IPX5, while this image indicates IPX6.
6. Troubleshooting
| Problem | Solution |
|---|---|
| Headphones not turning on | Ensure headphones and charging case are fully charged. Place headphones in the case and close the lid, then open again. |
| Cannot pair with device |
|
| No sound or low volume |
|
| Intermittent connection |
|
7. Specifications
| Feature | Detail |
|---|---|
| Model | AC210 |
| Bluetooth Version | 5.4 |
| Audio Driver Type | Dynamic Driver (12mm) |
| Battery Life (Headphones) | Up to 6 hours (single charge) |
| Total Playback Time | Up to 30 hours (with charging case) |
| Charging Port | USB-C |
| Control Method | Touch |
| Water Resistance | IPX5 |
| Item Weight | Approx. 5.3 ounces (0.15 kg) |
| Compatible Devices | Smartphones, Tablets, Laptops, Desktops, Gaming Consoles, Smart TVs |
| Material | Silicone |
8. Warranty and Support
For warranty information and customer support, please refer to the official Monster website or contact your retailer. Keep your proof of purchase for warranty claims.
Manufacturer: Monster





