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Cooler Master MasterBox Q300L Micro ATX Tower w/ Magnetic Design Dust Filter, Transparent Acrylic Side Panel, Adjustable I/O & Fully Ventilated for Airflow, MCB-Q300L-KANN-S00

In stock.
Ships from United States.
  • Box E500L
  • Box Lite 3.1
  • Box Lite 3.1 TG
  • Box Q300L
  • Box E300L
  • Box Q500L
  • Box MB311
  • Box MB320
  • ARGB
  • Blue LED
  • Red LED
  • Non-LED
  • Solid Panel
  • Tempered Glass
  • Transparent Panel
  • I/O panel can be adjusted in 6 different locations and the Case can be positioned: vertical or horizontal
  • Edge-to-Edge Acrylic Transparent Side Panel offers a full view inside
  • Body depth height: can support normal size ATX power supply
  • Front Magnetic Design Dust Filter with open perforated front, top and bottom for high air performance
  • Extra space behind the motherboard tray for hidden cable management
Cooler Master

Choose Your Style

The MasterBox Q300L is your straightforward option in the MasterBox Q-series from Cooler Master, a series that might be small in size but excels in functionality, modularity, and thermal performance.

Cooler Master

System Flexibility

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.

Cooler Master

Magnetic Dust Filters

Patterned magnetic filters create a unique look for your chassis while keeping your system's internals free from excess dust.

Cooler Master

Small Form Factor, ATX PSU Support

Despite the Micro-ATX form factor and the body depth/height of only 370 x 370mm, the MasterBox Q300L can accommodate a normal ATX PSU.

Cooler Master

Edge-to-Edge Acrylic Side Panel

Show off your build through the full size transparent side panel.

Cooler Master

Thermal Performance

The open design of the perforated front, top, and bottom guarantees excellent thermal performance.

Cooler Master

Routing Space

A space 28mm-wide behind the motherboard tray offers open space for hidden cable management.


  Cooler Master Cooler Master
  Q300L Q300P
Product Number MCB-Q300L-KANN-S00 MCB-Q300P-KANN-S02
Available Color Black Black
Materials Steel, Plastic Steel, Plastic
Dimensions, L x W x H 387 x 230 x 378mm 450 x 230 x 450mm
Motherboard Suport Micro-ATX, Mini-ITX Micro-ATX, Mini-ITX
Expansion Slots 4 4
Drive Bays 5.25" 0 0
3.5" HDD 1 1
2.5" SSD 2 2
I/O Port USB 3.0 x 2, Audio In/Out USB 3.0 x 2, Audio In/Out
Pre-Installed Fan(s) Front n/a 120mm RGB LED x2
Rear 120mm x1 120mm non-LED x1
Fan Support Front 120 / 140mm x2 120 / 140mm x2
Top 120mm x2 120mm x2
Rear 120mm x1 120mm x1
Bottom 120mm x1 120mm x1
RGB Controller Included Included
Radiator Support Front 120mm x1 / 240mm x1 120mm x1 / 240mm x1
Rear 120mm x1 120mm x1
Clearances CPU Cooler 157mm 157mm
PSU 160mm 160mm
GPU 360mm 360mm
Cable Routing Behind MB Tray 28mm 28mm
Dust Filters Bottom Bottom
Power Supply Support Bottom Mount, ATX PS2 Bottom Mount, ATX PS2
EAN Code 4719512065488 4719512065518
UPC Code 884102038006 884102038037
Net Weight 3.7 kg 5.2 kg
Gross Weight 4.7 kg 6.4 kg
Carton Dimensions, L x W x H 435 x 276 x 461mm 510 x 277 x 527mm

Warranty & Returns

Warranty, Returns, And Additional Information


  • Limited Warranty period (parts): 1 year
  • Limited Warranty period (labor): 1 year
  • Read full details

Return Policies

  • Return for refund within: 30 days
  • Return for replacement within: 30 days
  • This item is covered by's Standard Return Policy