Gear Up, Cool Off

Fine Mesh Front Panel
Mesh Intakes
Dual ARGB Fans
Optimized Airflow
Tempered Glass Side Panel
Adaptable Drive Cage
Versatile Cooling Options
Room For Upgrades

Gaming On Wide-open Throttle
The MasterBox MB311L ARGB is a Micro-ATX airflow PC case pre-installed with two ARGB fans and made to be built with the latest gaming hardware. The front panel's façade is made entirely of Fine Mesh, placed between two honeycomb vents on either side to maximize airflow. Since running the latest games, smoothly, means keeping the latest hardware efficiently cooled, top panel ventilation offers the option to add even more cooling hardware - if nothing is mounted, the top panel acts as passive ventilation.

The internal layout was engineered for a high compatibility for the latest gaming hardware while also accounting for future upgrades. Following in the principles of the award-winning MB Series, versatility is paired with presentation to ensure that any gaming system built inside the MasterBox MB311L ARGB looks as good as it performs.
Fine Mesh Front Panel
Cooler Master's Fine Mesh design on the front panel is proven to provide proficient airflow while filtering out dust.
Mesh Intakes
Large, mesh intakes span each side of the front panel to provide additional airflow to system.
Dual ARGB Fans
Two pre-installed 120mm ARGB fans can be managed by the motherboard, and connected by the included splitter, to create a comprehensive ARGB lighting system.
Optimized Airflow
Airflow is optimized by a collaboration between the Fine Mesh front panel, additional mesh intakes, top panel ventilation, and rear exhaust.
Tempered Glass Side Panel
Hardware, custom-loop cooling, and the pure pride of the builder is shown in panoramic view through an edge-to-edge tempered glass side panel.
Adaptable Drive Cage
The drive cage is able to shift toward the front to accommodate for PSU space, backwards to provide additional radiator space, or even completely removed.
Versatile Cooling Options
Support for up to six fans and front, top, and rear radiator support ensure that performance is not compromised.

Room For Upgrades
Support for up to a 344mm graphics card, a 166mm CPU cooler, and up to a 325mm PSU in length provides room for upgrades to stay ahead of the game.
​The small ARGB Controller is a mini-sized controller that allows your Addressable RGB such as fans and LED strips to be powered and controlled even in PC systems without an A-RGB capable motherboard.​

The controller comes with 14 lighting presets to make full use of the Addressable LEDs in the system and also allows to be completely switched off by long pressing its button.​

It is also possible to attach any external 2pin button to it to be able to switch presets without having to open the system. For ease of use, Cooler Master allows the RESET button to be optionally connected to the controller and used as an external ARGB preset switch button.
Product Name MasterBox MB311L ARGB MasterBox MB311L ARGB w/ controller
Product Number MCB-B311L-KGNN-S01 MCB-B311L-KGNN-S02
Exterior Color Black
Materials - Body Steel, Mesh, Plastic
Materials - Windowed Side Panel Tempered Glass
Dimensions (LxWxH) - incl. Protrusions 435.5 x 217.5 x 410mm
Dimensions (LxWxH) - excl. Protrusions 366.5 x 210 x 400mm
Volume (Liters excl. Protrusions) 30.79L
Motherboard Support Mini-ITX, Micro-ATX
Expansion Slots 4
5.25" Drive Bays (ODD) N/A
3.5"/2.5" Drive Bays (Combo) 2
2.5" Drive Bays (SSD) 2
I/O Panel - USB Ports 2 x USB 3.2 Gen 1 (USB 3.0)
I/O Panel - Audio In / Out 1x 3.5mm Audio Jack
1x 3.5mm Mic Jack
I/O Panel - Other 1 x ARGB 2-to-3 Splitter 1 x ARGB Controller
1 x ARGB 2-to-3 Splitter
Pre-installed Fan(s) - Top N/A
Pre-installed Fan(s) - Front 2 x 120mm ARGB fans
Pre-installed Fan(s) - Rear N/A
Pre-installed Fan(s) - Bottom N/A
Fan Support - Top 2 x 120mm / 2 x 140mm
Fan Support - Front 3 x 120mm* / 2 x 140mm
(*can only mount behind the front plate)
Fan Support - Rear 1 x 120mm
Radiator Support - Top 120 / 240mm
Radiator Support - Front 120 / 140 / 240 / 280mm
Radiator Support - Rear 120mm
Clearances - CPU Cooler 166mm
Clearances - Power Supply 325mm (w/o front radiator & drive cage)
140mm (drive cage in backmost position)
Clearances - Graphics Card 344mm
Cable Routing - Behind MB Tray 18~22mm
Dust Filters Front, Top, Bottom
Power Supply Support Bottom Mount, ATX
Warranty 2 years
EAN Code 4719512097298 4719512097595
UPC Code 884102069598 884102069895