Lian Li B4-mATX White SFF Micro ATX Mesh PC Gaming Case
Lian Li B4-mATX Chassis, Small Form Factor, White, 2x 120mm Fans, USB-C / USB-A, 3.5mm, mATX
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B4 mATX Modular Small Form Factor Case from Lian Li
Minimalist on the Outside, Maximalist on the InsideDeveloped in collaboration with DAN Cases, the Lian Li B4 mATX redefines what builders can expect from a compact PC chassis. Packing impressive hardware compatibility into a remarkably small 21.3-litre footprint, the B4 mATX supports powerful gaming and workstation hardware while offering the flexibility to be displayed horizontally or vertically. With support for full-sized graphics cards, ATX or SFX power supplies, extensive cooling options, and a choice of mesh or real wood front panels, the B4 mATX seamlessly blends performance-focused engineering with premium aesthetics.
Small Footprint, Big Hardware Support
Masterfully EngineeredDespite measuring just 21.3 litres in volume, the B4 mATX delivers exceptional component compatibility. The chassis supports micro-ATX motherboards, graphics cards up to 358.9mm in length and four slots thick, as well as CPU air coolers up to 166.5mm tall. Builders can also choose between ATX power supplies up to 140mm in length or compact SFX units, allowing the case to accommodate a wide variety of high-performance builds.
358.9mmQuad-slot GPU Support
166.5mmMax. Air Cooler
MicroATX / MiniITXMotherboard Support
ATX / SFXPower Supply
In Collaboration with DAN Cases
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The B4-mATX is the result of a collaboration between Lian Li and Dan Cases, bringing together the expertise of two renowned brands. Dan Cases is known for its innovative approach to compact, high-performance case design, where efficiency and simplicity are key. This partnership is significant because it merges Lian Li’s reputation for exceptional build quality with Dan Cases’ minimalist, highly functional designs. The outcome is a case that doesn’t just look good—it optimises every inch, offering a new standard of performance in a compact form.
Out-of-Box Airflow
Pre-Installed 120mm Slim Dual FansTo maximise airflow in its compact design, the B4 mATX ships with two pre-installed 120mm wide and 15mm slim fans mounted on a removable top bracket. These fans operate as exhaust by default but can be reconfigured to improve airflow depending on the chosen cooling setup. The removable bracket also simplifies cable routing and system assembly.
0 ~ 1800 RPMSpeed Range
30.3 dBANoise Level
2.4 mmH2OStatic Pressure
64.2 CFMMax. Airflow
Cooling That Scales with Your Build
The B4 mATX offers impressive cooling flexibility for a chassis of its size. Using an SFX power supply unlocks support for radiators up to 360mm, while ATX power supplies allow installation of radiators up to 240mm. Additional fan mounting positions across the side, bottom, front, and rear of the chassis give builders the freedom to optimise airflow for air-cooled or liquid-cooled systems.
Modular Design
Rotatable InletA rotatable AC inlet and generous rear clearance ensure tidy cable routing and easy access to motherboard I/O regardless of orientation.
Removable Fan BracketAllows large graphics vards slide in from the front side for a smoother, satisfying installation.
Reversible Fan BracketThe exhaust bracket can be installed outward to create more AIO clearance, or inward to improve air cooling.
Flexible Storage Support
The B4 supports a 2.5" SSD at the front with space at the bottom for either a 3.5" HDD or another SSD. Rest assured knowing there's still room for legacy storage.
Premium Finish
Essential I/OAll the ports you need are easily accessible in both orientations. Plug in right away with dual USB 3.0 Type-A ports, a combo audio jack and USB 3.2 Type-C for faster, modern transfers.
