Lian Li Dan-B4 Black

Build like never B4
Co-developed with DAN Cases, the B4-mATX’s modular design unlocks versatile build possibilities. With multiple color, panel, and layout options, plus an optional accessory, it adapts to a wide range of styles.

Compact Design, Broad Compatibility
With a compact 21.3L volume, the B4-mATX delivers impressive hardware compatibility, supporting M-ATX motherboards, 360mm AIOs, 140mm ATX PSUs, and up to 358mm 4-slot GPUs.

Minimal Design,Multiple Styles
The B4-mATX offers a clean mesh panel for an airflow-focused look or a real wood panel for a warmer, refined setup. Both support front-to-back airflow, balancing cooling performance with a streamlined exterior.

Vertical Mode,Maximized Desk Space
The vertical layout improves desk space efficiency by up to 30%. Integrated rear feet allow quick and easy switching between different usage modes.

Rotatable AC Power Connector
Designed for both horizontal and vertical configurations, the rotatable AC inlet adapts to your setup. Face it outward for convenient cable access, or rotate it inward in vertical mode to avoid clearance limitations.

REVERSIBLE Rear Fan Bracket
The rear fan bracket features a reversible design for greater layout flexibility. It can be installed outward to create more clearance for liquid cooling, or inward to position the fan closer to the CPU airflow path and improve CPU air-cooling performance by up to 1°C.

Recommended Liquid Cooling Configuration
The B4-mATX supports 360mm and 280mm radiators with up to 52mm total thickness.

Extra Intake, Better Cooling
Supports a 120 × 120 × 15mm slim front fan with an SFX PSU and GPU under 343mm long, helping improve intake airflow.

PRE-INSTALLED 15MM SLIM FANS,
Flexible Airflow Design
Two pre-installed 120 × 120 × 15mm slim fans on the top provide enhanced cooling performance. Operating up to 1800 RPM, they are daisy-chained to reduce cable clutter.

Flexible GPU & Fan Support
Supports up to 358mm long 4-slot graphics cards. Bottom fan support varies by GPU thickness: 2.5-slot GPUs support 25mm fans, 3-slot GPUs support 15mm slim fans, and 3.5-slot or thicker GPUs do not support bottom fans.

Easy GPU Installation
The removable front fan bracket lets large graphics cards slide in from the front side of the chassis for a smoother installation process.

Pre-Installed
GPU Anti-Sag Bracket
Built to handle GPUs up to 4 slots thick and 358mm long, the case comes equipped with a dedicated anti-sag bracket to ensure stability and prevent sagging.

Modular Design, Easier Installation
Tool-less removable panels offer quick and easy access for installation and cable routing, while a removable bottom dust filter helps maintain a clean system.

Removable Top Fan Bracket
The removable top fan bracket provides easier access for routing and managing CPU 8-pin cables, while also making it simpler to configure the front-top fan as intake for air-cooler setups.

Easier Cable Management
Cable tie points around the PSU and top brackets help secure CPU 8-pin and PSU cables for a cleaner, more organized build.

In vertical mode, a removable bracket and rotatable cable guide work together to route cables cleanly through the bottom of the case.

Flexible Storage Support
Supports 1 x 2.5” SSD at the front, with space at the bottom for either 1 x 2.5” SSD or 1 x 3.5” HDD.

ACCESSIBLE CONNECTIVITY
The I/O layout keeps essential ports easy to reach in both traditional and vertical layouts, with a high-speed USB Type-C port supporting up to 20Gbps transfer speeds.

In Collaboration with DAN Cases
Co-developed with Daniel Hansen of DAN Cases, the B4-mATX combines flexible modularity with LIAN LI’s precision craftsmanship in a compact form.

Hard Compatibility
Tool-less removable panels offer quick and easy access for installation and cable routing, while a removable bottom dust filter helps maintain a clean system.