Features:

Q300L V3 is positioned as the most performance-ready entry in Cooler Master’s mATX lineup, delivering serious hardware compatibility within a small but capable footprint. Built under the Thermal Excellence philosophy, it prioritizes airflow optimization and practical hardware support, ensuring that smaller systems can still achieve strong cooling performance and stable operation.

As part of the QUBE family, Q300L V3 carries forward the series’ modular design philosophy, including flexible I/O placement, vertical or horizontal orientation, and support for optional accessories, such as handles. These modular elements bring the adaptable spirit of the QUBE ecosystem into the entry mATX segment.

Engineered to support longer GPUs and taller air coolers, Q300L V3 improves chassis rigidity and layout efficiency while maintaining a simple and approachable build experience for both DIY users and system integrators.

Q300L V3 (Lite Version)

Handle-free version retaining the Q300L design identity.

QUBE Family Modular DNA

Inspired by the modular philosophy of the QUBE family, Q300L V3 introduces flexible customization options for small but powerful builds. Optional handles, flexible front I/O placement, and front panel mounting points for 3D-printed accessories allow users to personalize both aesthetics and functionality. The chassis also supports vertical or horizontal placement

Thermal Performance Upgrade

Designed under Cooler Master’s Thermal Excellence philosophy, Q300L V3 enhances cooling capability with larger front panel perforations for improved airflow intake, support for up to 6 fans, and an upgraded 140 mm rear exhaust configuration. Increased CPU air cooler clearance up to 178 mm further enables strong air-cooling performance for mainstream high-TDP systems.

Improved Structure

An improved motherboard tray and optimized fan mounting layout enhance chassis stability, while enlarged front panel perforations improve airflow intake efficiency for better cooling performance.

Easy Build Experience

Optimized internal layout with 30 mm cable routing space enables clean cable management and an intuitive building process for both first-time builders and system integrators.

Hardware Compatibility

Supports GPUs up to 366 mm (without front fan installed) and accommodates mainstream high-TDP air coolers, ensuring strong hardware compatibility within a small form factor.

Fans Support

• Top: 2 x 120mm / 2 x 140mm
• Front: 2 x 120mm / 2 x 140mm
• Rear: 1 x 120mm / 1 x 140mm
• Bottom: 1 x 120mm / 1 x 140mm
• Side (Left/Right): NA

Radiator Support

• Top: 240 / 120 mm
• Front: 240 / 120 mm
• Rear: 120 mm
• Bottom: N/A
• Side (Left/Right): N/A

Clearances

• CPU Cooler: 178mm
• Power Supply: 200mm (without bottom fan installed) / 140mm (with bottom fan installed)
• Graphics Card: 366mm (without front fan installed)

Drive Bays

• 5.25” Drive Bay: NA
• 3.5” Drive Bay: 1
• 3.5”  / 2.5” Combo: 1
• 2.5” Drive Bay: 2 (max 4)