Does the fan included have LED on it?

No, it does not have an Led. It is a basic, three wire, fixed speed fan.

Can this hold a standard ATX board?

No. This is designed to work with micro ATX boards.

Does it come with a power supply?

No. This is a mATX case only. A power supply will need to be purchased separately. It only comes with one exhaust fan like the one you see in the product images. I recommend purchasing additional case fans in addition to a power supply.

"The case can be put in vertical or horizontal position" according to Cooler Master's website, does this include upside down?

If by upside down you mean with the power supply on top, then yes, it appears you can remove the feet, screen, etc and place them on the "top" or the "front". However, I'm not sure there are any fan screw holes on the "bottom" already.

is this a metal case?

the entire case is metal except the viewing panel,IO panel and the facade pieces on the edges

Does it come with the fan in the picture?

Hello Luke Camarillo, Thank you for contacting us in regards to your question. Yes it'll come with 1 120mm fan pre installed in the back. Thank you and have a nice day! Newegg Support

can this case hold 2x 3.5 HDD ??

Yes, but I do not recommend this case. The plastic that houses the power and peripheral ports is extremely flimsy. It is thin plastic that is only attached at the two end screws with no support behind it. Power button is very cheap and will break. Mine already has. If it wasn't for this, I would be pleased with the price point of this case.

Does this case have external drive bays?

No it does not. Everything is internal. The front and top has mesh filters for dust, but that is about it.

what do i need to add to it so it will work?

As a paperweight, Nothing. As a bare minimum computer, Motherboard, CPU, PSU, RAM, And OS. Of course, A monitor, mouse, keyboard might help as well. If you plan on gaming a GPU is recommended.

What type of connecters on the fan in the back?

Standard 3-pin fan connector, if memory serves me. Nothing special about it.

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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

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Options: MasterBox Q300L (Black)

MasterBox Q300L (Black)
MasterBox Q300LV2 (Black)
MasterBox Q300LV2 (White)

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

🔥Don't forget your OS, we have Windows 11 OEM, Download and USB versions available

Overview

Specs

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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.

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.

Magnetic Dust Filters

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

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.

Edge-to-Edge Acrylic Side Panel

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

Thermal Performance

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

Routing Space

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

The MasterBox Q300L 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.

Best Seller Ranking	#87 in Computer Cases

Model
Brand	Cooler Master
Series	MasterBox Q300L
Part Number	MCB-Q300L-KANN-S00

Details
Type	Micro ATX Tower
Color	Black
Case Material	Steel / Plastic
With Power Supply	No
Power Supply Mounted	Bottom
Motherboard Compatibility	Micro ATX / Mini ITX
Side Panel Window	Yes
Dust Filters	Bottom

Expansion
Internal 3.5" Drive Bays	1
Internal 2.5" Drive Bays	2
Hot-Swap Drive Bays	0
Expansion Slots	4

Front Panel Ports
Front Ports	2 x USB 3.0, 2 x Audio

Cooling System
Fan Options	Front - 2 x 120mm / 2 x 140mm fan Rear: 1 x 120mm fan (Pre-installed) Top: 2 x 120mm fan Bottom: 1 x 120mm fan
Radiator Options	Front - Up to 240mm / Rear - Up to 120mm
80mm Fans	No
140mm Fans	No
Side Air duct	Yes

Dimensions & Weight
Max GPU Length	360 mm
Max CPU Cooler Height	157 mm
Max PSU Length	160 mm
Dimensions	15.00" x 9.06" x 15.24"
Weight	8.16 lbs.

Additional Info
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 MasterBox Q300L 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. Edgo-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.

Additional Information
First Listed on Newegg	February 12, 2018

Warranty & Returns

Warranty, Returns, And Additional Information

Warranty

Limited Warranty period (parts): 2 years
Limited Warranty period (labor): 2 years
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Return Policies

We want to ensure your holiday shopping this year is hassle-free. That’s why we’re automatically extending our return policies on almost every product! For purchases placed between November 1st, 2025 and December 31, 2025 you will have until January 31, 2026 to return your product.

Return for refund until: January 31, 2026

Return for replacement until: January 31, 2026

This item is covered by Newegg.com's Extended Holiday Return Policy.
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Manufacturer Contact Info

Manufacturer Product Page
Manufacturer Website
Support Phone: 1-888-624-5099
Support Email: customersupport@coolermaster.com
Support Website
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