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Cooler Master Introduces Q300L V3, the Next Generation of its Popular mATX Case

The Q300L V3 builds on the familiar identity of the Q300L series while addressing the needs of modern compact systems. With support for Mini-ITX and microATX motherboards, CPU air coolers up to 178 mm tall, graphics cards up to 366 mm long, and up to six fans, the case gives builders more room to work while keeping the small footprint that made the series popular.
Airflow is a major focus of the updated design. Enlarged front-panel perforations help increase intake potential, while support for a 140 mm rear exhaust fan gives builders more flexibility when tuning system cooling. The case also provides room for CPU air coolers up to 178 mm tall, expanding cooler compatibility in a compact chassis.
Cooler Master also improved the chassis structure for a more reliable building experience. Reinforced fan mounts, an upgraded motherboard tray, and a tempered glass side panel help the Q300L V3 feel more solid and refined than previous generations. For system integrators and high-volume builders, those improvements help support cleaner assembly, more consistent results, and a stronger finished system.
A modern front I/O gives the case a practical update for today’s users. The I/O ports include 3 USB 3.2 Gen 2×2 Type-C, dual USB 3.2 Gen 1 Type-A, and a combo audio jack, giving builders convenient access to high-speed connectivity without complicating the case layout.
Key Features
- Compact microATX Platform – Supports Mini-ITX and microATX motherboards in a compact footprint designed for desks, dorms, gaming setups, and system integrator builds.
- Improved Airflow Potential – Enlarged front-panel perforations, support for up to six fans, and 140 mm rear exhaust compatibility help improve cooling options for modern components.
- Room for Modern Hardware – Supports CPU air coolers up to 178 mm tall and graphics cards up to 366 mm long, giving builders more flexibility in a smaller case.
- Stronger Chassis Structure – Reinforced fan mounts, an upgraded motherboard tray, and a tempered glass side panel create a more stable, refined build experience.
- Updated Front I/O – Includes 3 USB 3.2 Gen 2×2 Type-C, dual USB 3.2 Gen 1 Type-A, and a combo audio jack for modern connectivity.
- QUBE 340 Alternative – The QUBE 340 adds optional handles, vertical or horizontal orientation, flexible front I/O placement, and front accessory mounting support for users who want more modularity.
For users who want more customization, Cooler Master will also offer the QUBE 340, a modular companion version built on the same core platform. The QUBE 340 adds optional handles, vertical or horizontal orientation, flexible front I/O placement, and front mounting support for compatible 3D-printable accessories. It brings the modular spirit of the QUBE family to the same compact microATX foundation, giving builders a more expressive alternative to the streamlined Q300L V3.
Together, the Q300L V3 and QUBE 340 give builders two ways to approach the same improved compact case platform. The Q300L V3 offers a clean, accessible upgrade for mainstream microATX builds, while the QUBE 340 adds more flexibility for users who want a case that can adapt to their setup, space, and style.











