Cooler Master MasterBox Q300L Case, Black, Mini Tower, 2 x USB 3.0 Type-A, Edge-to-Edge Acrylic Transparent Side Panel, Unique Patterned Front & Top Dust Filter, Modular I/O Panel, Vertical or Horizontal Positioning
SKU: 67323436296

Cooler Master MasterBox Q300L Case, Black, Mini Tower, 2 x USB 3.0 Type-A, Edge-to-Edge Acrylic Transparent Side Panel, Unique Patterned Front & Top Dust Filter, Modular I/O Panel, Vertical or Horizontal Positioning

Sale price$55.58 Regular price$61.75
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Ships within 48 hours · Estimated delivery Jul 7 - Jul 12

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Description

Cooler Master MasterBox Q300L Case, Black, Mini Tower, 2 x USB 3.0 Type-A, Edge-to-Edge Acrylic Transparent Side Panel, Unique Patterned Front & Top Dust Filter, Modular I/O Panel, Vertical or Horizontal PositioningThe MasterBoxQ300L is your straightforward option in the lineup of the brand new MasterBox Q series from Cooler Master. A series that might be small in size but excels in functionality and modularity without compromising on the thermal performance. Although the size wouldnt tell, the MasterBox Q300L supports a standard ATX PSU which we dont see often in the market with this size. Based on the different system setup, the I O panel can be adjusted to

The MasterBoxQ300L is your straightforward option in the lineup of the brand new MasterBox Q-series from Cooler Master. A series that might be small in size but excels in functionality and modularity without compromising on the thermal performance.

Although the size wouldn’t tell, the MasterBox Q300L supports a standard ATX PSU which we don’t see often in the market with this size. Based on the different system setup, the I/O panel can be adjusted to six different locations, three options at each side of the case. You can decide which setup fits your system best.

Due to the cube design of the frame and special pattern design on the magnetic dust filter will make the chassis stand out from the rest. The combination of a practical design and the unique customizable outlook makes the MasterBox Q300L the perfect choice for office and home usage.

Features
- High Flexibility for System Building: The I/O panel can be adjusted to six different locations. On both side of the body you can install the I/O panel at the front, top or bottom.
- Minimized Dimension with ATX PSU Support: Despite the Micro-ATX form factor and the body depth and height of only 370mm x 370mm, the MasterBoxQ300L can accommodate a normal ATX PSU.
- Patterned Dust Filter: Special pattern on the dust filter creates a unique outlook for the chassis.
- Clean Routing Space: Behind the motherboard tray, it offers 28mm wide and spacy room for hidden cable management.
- Excellent Thermal Performance: The open design of the perforated front, top and bottom guarantees excellent thermal performance.
- Edge-to-Edge Acrylic Transparent Side Panel: Show off your build through the full size transparent side panel.
- Vertical and Horizontal Position: The case can be put in vertical and horizontal position.

Model
MasterBox Q300L
MCB-Q300L-KANN-S00

Colour
Black

Materials
Steel
Plastic

Dimensions ( L x W x H )
387 x 230 x 378 mm

Motherboard Support
Micro ATX
Mini-ITX

Expansion Slots
4

Drive Bays
5.25": 0
3.5" HDD: 1
2.5" SSD: 2

I/O Port
2 x USB 3.0
Audio In / Out

Pre-Installed Fans
Front: N/A
Rear: 1 x 120mm

Fan Support
Front: 2 x 120/140mm
Top: 2 x 120mm
Rear: 1 x 120mm
Bottom: 1 x 120mm

Radiator Support
Front: 1 x 120/240mm
Rear: 1 x 120mm

Clearances
CPU Cooler: 157mm
PSU: 160mm
GPU: 360mm

Cable Routing
Behind MB Tray: 28mm

Power Supply Support
Bottom mount
ATX PS2
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 67323436296

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Sherry L Thomson
Whiting, US
★★★★★ 5
Warmth
Size: One Size, Color: (001) Black / Pewter / Ghost Gray
As expected
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Reviewed in the United States on December 5, 2025
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Opinion from K
Charlottesville, US
★★★★★ 5
Pretty in Pink
Size: One Size, Color: (652) Rebel Pink / Black / White
Great shade of pink, fits well.
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Reviewed in the United States on October 29, 2023
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J Margaret
Birmingham, US
★★★★★ 5
Soft and comfy and so warm.
Size: One Size, Color: (500) Misty Purple / Dark Maroon / Misty Purple
Really nice hat. Love it. Wear it daily. Just as pictured and surprisingly soft.
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Reviewed in the United States on March 9, 2024
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esalomo
Chelsea, US
★★★★★ 3
Fits ok
Size: One Size, Color: (003) Black / / Castlerock
Fits ok
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Reviewed in the United States on December 25, 2025
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Happy Momma
Phoenix, US
★★★★★ 5
Love this
Size: One Size, Color: (001) Black / Pewter / Ghost Gray
Very comfortable and warm
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Reviewed in the United States on January 8, 2025

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