---
product_id: 59059637
title: "Cooler Master MasterBox Q300L Micro-ATX PC Case – Compact mATX Computer Case with Magnetic Dust Filters, Modular Adjustable I/O Panel, Perforated Airflow Design, 1 x 120mm Pre-Installed Fan, Black"
brand: "cooler master"
price: "€ 115.43"
currency: EUR
in_stock: true
category: "Cooler Master"
url: https://www.desertcart.ie/products/59059637-cooler-master-masterbox-q300l-micro-atx-pc-case-compact-matx
store_origin: IE
region: Ireland
---

# Magnetic dust filters with unique pattern Perforated airflow + 1x120mm fan pre-installed Supports Micro-ATX & Mini-ITX boards Cooler Master MasterBox Q300L Micro-ATX PC Case – Compact mATX Computer Case with Magnetic Dust Filters, Modular Adjustable I/O Panel, Perforated Airflow Design, 1 x 120mm Pre-Installed Fan, Black

**Brand:** cooler master
**Price:** € 115.43
**Availability:** ✅ In Stock

## Summary

> 🖤 Small Frame, Big Performance — Build Bold, Stay Cool!

## Quick Answers

- **What is this?** Cooler Master MasterBox Q300L Micro-ATX PC Case – Compact mATX Computer Case with Magnetic Dust Filters, Modular Adjustable I/O Panel, Perforated Airflow Design, 1 x 120mm Pre-Installed Fan, Black by cooler master
- **How much does it cost?** € 115.43 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.ie](https://www.desertcart.ie/products/59059637-cooler-master-masterbox-q300l-micro-atx-pc-case-compact-matx)

## Best For

- cooler master enthusiasts

## Why This Product

- Trusted cooler master brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Clean & Stylish:** Magnetic dust filters with a distinctive pattern keep your system pristine and visually striking.
- • **Showcase Your Build:** Edge-to-edge transparent side panel lets your meticulously crafted rig steal the spotlight.
- • **Compact Yet Spacious:** Fits large GPUs up to 360mm and CPU coolers up to 159mm in a sleek micro-ATX frame.
- • **Optimized Cooling Design:** Perforated panels on all sides plus support for up to 5 fans and 240mm liquid cooling keep your build chill.
- • **Modular I/O Panel Flexibility:** Customize your setup with 6 adjustable I/O panel positions for ultimate convenience.

## Overview

The Cooler Master MasterBox Q300L is a compact Micro-ATX PC case designed for professionals who demand modularity and superior airflow. It supports large GPUs and CPU coolers, features a fully perforated design for optimal cooling, and offers a uniquely adjustable I/O panel with magnetic dust filters. Its transparent side panel and distinctive dust filter pattern make it a standout choice for stylish, high-performance builds in limited spaces.

## Description

The Master Box Q300L is your straightforward option in the lineup of the brand new Master Box 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 Master Box 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 Master Box Q300L The perfect choice for office and home.

## Features

- Ample Interior: Explore ample interior space for Micro-ATX or Mini-ITX motherboards, ensuring easy and future expansion
- Components Clearance: Accommodates CPU coolers with a max height of 159mm, GPU cards up to 360mm, and PSU up to 160mm in length.
- Versatile Cooling: Maximize cooling performance with a 240mm liquid cooler and 5 fans.
- Modular I/O Panel: You have the flexibility to adjust its position at the front, top, or bottom on both sides
- Edge-To-Edge Panel: Show off your meticulous build through the transparent side panel with pride.
- Open Thermal Design: The perforated design on all sides promotes optimal airflow and heat dissipation
- Magnetic Dust Filters: The unique pattern of the dust filter adds a distinctive appearance to the case.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0785GRMPG |
| Antenna Location | Gaming |
| Best Sellers Rank | #6 in Computer Cases |
| Brand | Cooler Master |
| Built-In Media | 1 computer case |
| Case Type | Mini-Tower |
| Color | Black |
| Compatible Devices | Micro-ATX and Mini-ITX motherboards, Cooler Master devices |
| Cooling Method | Air |
| Customer Reviews | 4.5 4.5 out of 5 stars (13,967) |
| Enclosure Material | Alloy Steel, Plastic |
| Global Trade Identification Number | 00884102038006, 00884102095313, 04719512065488 |
| Hard Disk Form Factor | 3.5 Inches |
| Internal Bays Quantity | 1 |
| Item Dimensions D x W x H | 15.39"D x 9.06"W x 15"H |
| Item Type Name | grocery |
| Item Weight | 480 Grams |
| Manufacturer | Cooler Master |
| Mfr Part Number | MCB-Q300L-KANN-S00 |
| Model Name | Q300L |
| Model Number | MCB-Q300L-KANN-S00 |
| Number of Fans | 3 |
| Other Special Features of the Product | Accomodates CPU Coolers, Adjustable, Dust Filter, Edge-To-Edge Panel, Fully Ventilated |
| Power Supply Maximum Output | 500 Watts |
| Power Supply Mounting Type | Bottom Mount |
| Supported Motherboard | Micro-ATX and Mini-ITX |
| Total Expansion Slots Quantity | 4 |
| Total USB 3.0 Ports | 2 |
| Total Usb Ports | 2 |
| UPC | 884102095313 884102038006 |
| Warranty Description | 2 |

## Product Details

- **Brand:** Cooler Master
- **Case Type:** Mini-Tower
- **Color:** Black
- **Cooling Method:** Air
- **Item Weight:** 480 Grams
- **Material:** Alloy Steel, Plastic
- **Model Name:** Q300L
- **Motherboard Compatability:** Micro-ATX and Mini-ITX
- **Power Supply Mounting Type:** Bottom Mount
- **Recommended Uses For Product:** Gaming

## Images

![Cooler Master MasterBox Q300L Micro-ATX PC Case – Compact mATX Computer Case with Magnetic Dust Filters, Modular Adjustable I/O Panel, Perforated Airflow Design, 1 x 120mm Pre-Installed Fan, Black - Image 1](https://m.media-amazon.com/images/I/91UOdM9izhL.jpg)

## Available Options

This product comes in different **Color, Style** options.

## Questions & Answers

**Q: Is this case wide enough to support a cooler master hyper 212 evo?**
A: I know what the official CM specs are, but I think it will fit.  This guy installed a taller cooler with its cover and it fit.  https://www.vortez.net/articles_pages/cooler_master_masterbox_q300l_review,8.html

**Q: I've seen photos of the handle (from a Q300P) being attached to the center of the top panel of this case. Is this possible?**
A: You can remove the plastic bit that has the cooler master logo on it and install handles on the case like the Q300P

**Q: what are the size and placements of the fans?**
A: There are 3 fans (120mm) in total. 1 exhaust fan in the rear, and 2 intake fans at the front.

-CM Myke

**Q: Does the case come pre-assembled?**
A: Hello Kevin,

The case does come assembled, but you will need to plug in the connectors, and open it up to install your components.

CM-PNguyen

## Frequently Bought Together

- Cooler Master MasterBox Q300L Micro-ATX Tower with Magnetic Design Dust Filter, Transparent Acrylic Side Panel, Adjustable I/O & Fully Ventilated Airflow, Black (MCB-Q300L-KANN-S00)
- AMD Ryzen 5 5500 6-Core, 12-Thread Unlocked Desktop Processor with Wraith Stealth Cooler
- Thermaltake Smart 500W 80+ White Certified PSU, Continuous Power with 120mm Ultra Quiet Cooling Fan, ATX 12V V2.3/EPS 12V Active PFC Power Supply PS-SPD-0500NPCWUS-W

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*Product available on Desertcart Ireland*
*Store origin: IE*
*Last updated: 2026-07-16*