1. Introduction
Thank you for choosing the Monster Open Ear Headphones AC330. These wireless earbuds are designed to provide a comfortable and immersive audio experience while keeping you aware of your surroundings. Featuring Bluetooth 5.4 technology, a stylish rotating charging case with a lanyard, and IPX5 water resistance, these headphones are perfect for all-day use, whether you're working out, commuting, or simply enjoying your favorite music.
Please read this manual carefully before using your headphones to ensure proper operation and to maximize their lifespan.
2. What's in the Box
- Monster Open Ear AC330 Headphone (2)
- Charging Case (1)
- Type-C Charging Cable (1)
- Silicone Lanyard (1)
- Quick Start Guide (1)
- User Manual (1)

Figure 2.1: Contents of the Monster Open Ear AC330 package. This includes the two open-ear headphones, their circular rotating charging case, a USB-C charging cable, a silicone lanyard, and the quick start guide and user manual.
3. Product Specifications
| Feature | Specification |
|---|---|
| Model Name | Open AC330 |
| Brand | Monster |
| Connectivity Technology | Wireless (Bluetooth 5.4) |
| Audio Driver Size | 14.2 Millimeters |
| Ear Placement | Open Ear |
| Control Type | Touch Control |
| Battery Life (Single Charge) | Up to 8 hours |
| Total Battery Life (with Charging Case) | Up to 24 hours |
| Water Resistance Rating | IPX5 |
| Item Weight (each earbud) | 7g (approx.) |
4. Setup and First Use
4.1 Charging the Case and Earbuds
Before first use, fully charge the charging case and earbuds. Connect the provided Type-C charging cable to the charging port on the case and plug the other end into a USB power source (e.g., computer, wall adapter). The indicator lights on the case will show charging status.

Figure 4.1: The charging case with earbuds inserted, connected via USB-C cable for charging. Indicator lights on the case illuminate to show charging progress.
Video 4.1: A demonstration of charging the Monster Open Ear Headphones AC330. The video shows the earbuds being placed into the charging case and the USB-C cable being connected to initiate charging, with indicator lights confirming the process.
4.2 Pairing with Your Device
- Ensure earbuds are charged and in pairing mode (flashing light).
- Open the charging case. The earbuds will automatically enter pairing mode, indicated by a flashing light on the earbuds.
- On your device (smartphone, tablet, etc.), go to Bluetooth settings.
- Select "Monster Open Ear AC330" from the list of available devices.
- Once connected, a voice prompt will confirm successful pairing, and the indicator lights on the earbuds will turn off or show a steady light.

Figure 4.2: A visual representation of the Bluetooth pairing process, showing the headphones connected to a smartphone. The image highlights the Bluetooth 5.4 technology for stable connection.
5. Wearing the Earbuds
The Monster Open Ear AC330 headphones feature an ergonomic open-ear design with ear hooks for a secure and comfortable fit. This design allows you to remain aware of your surroundings while enjoying audio.
- Take the earbuds out of the charging case.
- Place the ear hooks behind your ears.
- Lightly twist the earbuds until they feel comfortable and secure in front of your ear canal.

Figure 5.1: The Monster Open Ear AC330 headphones worn by a user, illustrating the open-ear design and secure fit. The image emphasizes the lightweight and comfortable nature of the earbuds.
6. Operating Controls (Touch Control)
The Monster Open Ear AC330 headphones utilize touch controls for easy management of audio playback and calls.
| Action | Control |
|---|---|
| Play/Pause | Double-click (L/R earbud) |
| Voice Assistant | Hold for 2 seconds (L/R earbud) |
| Previous Song | Triple-click (L earbud) |
| Next Song | Triple-click (R earbud) |
| Answer Call | Double-click (L/R earbud) |
| Hang Up Call | Hold for 2 seconds (L/R earbud) |
| Volume Down | Single-click (L earbud) |
| Volume Up | Single-click (R earbud) |

Figure 6.1: A detailed guide to the touch controls on the Monster Open Ear AC330 headphones, including actions for music playback, call management, and voice assistant activation.
7. Maintenance and Care
- Cleaning: Regularly wipe the earbuds and charging case with a soft, dry cloth. Avoid using harsh chemicals or abrasive materials.
- Water Resistance: The headphones are IPX5 water resistant, meaning they can withstand sweat and light splashes. 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: When not in use, store the earbuds in their charging case to protect them and keep them charged.
- Temperature: Avoid exposing the headphones to extreme temperatures (hot or cold) as this can affect battery life and overall performance.

Figure 7.1: The Monster Open Ear AC330 headphones and their charging case, showcasing their compact and stylish design, ideal for daily use and easy maintenance.

Figure 7.2: The IPX5 water resistance of the Monster Open Ear AC330 headphones is demonstrated with water droplets on the earbuds, indicating their suitability for workouts and light outdoor activities.
8. Troubleshooting
| Problem | Possible Solution |
|---|---|
| Earbuds not pairing/connecting |
|
| No sound or low volume |
|
| Earbuds not charging |
|
| Sound cutting in/out |
|
9. Warranty and Support
For warranty information and customer support, please refer to the Quick Start Guide included in your package or visit the official Monster website. Keep your purchase receipt as proof of purchase for warranty claims.
Manufacturer: Monster





