COOLER MASTER · MASTERBOX SERIES
Cooler Master MasterBox Q300L White M-ATX Mid-Tower Cabinet
A compact white PC cabinet featuring a transparent acrylic side panel, flexible positioning, a modular I/O panel and versatile cooling support for Micro-ATX and Mini-ITX builds.
Key Highlights of Cooler Master MasterBox Q300L White
Clean White Finish
A white exterior for a clean, coordinated look in modern PC setups.
Transparent Side Panel
Full-size transparent acrylic side panel to showcase your PC components.
Flexible Cooling
Multiple fan mounting positions and support for front and rear radiators.
Flexible Positioning
Vertical or horizontal placement and a repositionable I/O panel.
Introduction to Cooler Master MasterBox Q300L White
The Cooler Master MasterBox Q300L White is a compact Mini Tower PC cabinet designed for users who want a practical chassis with a clean white finish. Supporting Micro-ATX and Mini-ITX motherboards, it provides a space-conscious foundation for everyday computers, home workstations and compact gaming systems.
Its full-size transparent acrylic side panel lets you showcase your internal components, while the modular I/O panel can be repositioned in six different locations. The cabinet can also be placed vertically or horizontally, giving you more flexibility when arranging your PC setup.
With support for graphics cards up to 360mm, CPU coolers up to 159mm and front radiators up to 240mm, the MasterBox Q300L White combines compact dimensions with useful component compatibility.
Features and Technologies
White Exterior Design
The white steel and plastic exterior gives the cabinet a clean appearance that works well with coordinated white PC components and accessories.
Transparent Acrylic Side Panel
The edge-to-edge transparent acrylic side panel provides a clear view of the internal components and lets you display your PC build.
Modular I/O Panel
The I/O panel can be adjusted to six different locations. It can be installed at the front, top or bottom on either side of the chassis.
Vertical and Horizontal Placement
The cabinet supports both vertical and horizontal positioning, offering flexibility for different desk arrangements and spaces.
Perforated Chassis Design
The perforated front, top and bottom sections help promote airflow through the cabinet for system cooling.
Clean Cable Management
A 28mm space behind the motherboard tray provides room to route and organise cables for a cleaner-looking build.
Flexible Cooling and Component Compatibility
The MasterBox Q300L White supports up to two 120mm or 140mm fans at the front, two 120mm fans at the top, one 120mm fan at the rear and one 120mm fan at the bottom. One 120mm rear fan is pre-installed. For liquid cooling, the front supports radiators up to 240mm, while the rear supports a 120mm radiator.
Technical Specifications
Cooler Master
MasterBox Q300L White
MCB-Q300L-WANN-S00
Mini Tower
White
Steel, Plastic
Micro-ATX, Mini-ITX
4
387 × 230 × 381mm
159mm
360mm
160mm
Bottom-Mounted ATX PS2
1
2
0
2 × 120mm / 140mm
2 × 120mm
1 × 120mm
1 × 120mm
1 × 120mm Rear Fan
120mm / 240mm
120mm
2 × USB 3.0
1 × 3.5mm Audio Jack
28mm Behind Motherboard Tray
Bottom
2 Years
Note: Specifications are based on the Cooler Master MasterBox Q300L White product information. Audio connectivity is listed as one 3.5mm audio jack for this white model. Check component dimensions and mounting requirements before purchasing.
Ideal Use Cases
Compact Gaming PCs
A practical option for Micro-ATX gaming systems with graphics cards up to 360mm long.
White PC Builds
The white exterior works well for users creating a coordinated white-themed computer setup.
Home and Office Systems
Its compact dimensions and flexible positioning make it suitable for home and office workspaces.
Custom PC Builds
The transparent side panel and modular I/O arrangement offer flexibility for personalised PC configurations.
Before You Buy / Install
- Confirm that your motherboard is Micro-ATX or Mini-ITX before purchasing.
- Check that your graphics card does not exceed the 360mm maximum supported length.
- Ensure your CPU cooler height is within the 159mm clearance limit.
- Verify that your ATX power supply is no longer than the supported 160mm clearance.
- The front supports up to a 240mm radiator, while the rear supports a 120mm radiator. Check radiator and component fit before installation.
- One 120mm rear fan is pre-installed. Additional fans required for your configuration must be purchased separately.
- Check the audio connector requirements of your headset, as this model lists one 3.5mm audio jack.
Frequently Asked Questions
Which motherboards are compatible with the Cooler Master MasterBox Q300L White?
The MasterBox Q300L White supports Micro-ATX and Mini-ITX motherboards.
Does the MasterBox Q300L White come with pre-installed fans?
Yes. It includes one pre-installed 120mm fan at the rear. Additional fans are not included in this specification.
What is the maximum graphics card length supported?
The cabinet supports graphics cards up to 360mm in length. Check your graphics card dimensions before installation.
Can I install a liquid cooler in the MasterBox Q300L White?
Yes. It supports a 120mm or 240mm radiator at the front and a 120mm radiator at the rear, subject to component clearance.
Does the cabinet support a standard ATX power supply?
Yes. The MasterBox Q300L White supports a bottom-mounted ATX PS2 power supply with a maximum specified clearance of 160mm.
Can the MasterBox Q300L White be placed horizontally?
Yes. The cabinet supports both vertical and horizontal positioning, giving users more flexibility when arranging their PC setup.
How many storage drives can be installed?
The listed drive bays include one 3.5-inch HDD bay and two 2.5-inch SSD bays.
What audio connectivity does the white version offer?
The official specification for the MasterBox Q300L White lists one 3.5mm audio jack. Check your headset's connector requirements before purchasing.
What is the warranty on the Cooler Master MasterBox Q300L White?
The manufacturer's listed warranty for the MasterBox Q300L White is 2 years. Please check the applicable warranty terms at the time of purchase.
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