Lian Li and DAN Cases Unveil B4-mATX Small-Form-Factor Case

The B4-mATX is designed for versatility and allows users to set up the system either as a traditional horizontal desktop or as a vertical tower. When set up vertically, the case takes up to 30 percent less space on the desk. To support this flexibility, the case features a rotatable power connector and a swiveling cable holder beneath the PCIe slots, which keeps the cabling secure and tidy regardless of the orientation.

Users can choose between various aesthetic and functional front panels. For those who prioritize maximum airflow, a version with a perforated grille is available, while a version made of real wood—available in either walnut or beech—offers a more harmonious, furniture-like appearance. Both the grille and wood versions are available in black or white.

Hardware and Cooling Integration

Despite its compact size, the B4-mATX supports a wide range of hardware. It accommodates graphics cards up to 358 mm in length and offers 162 mm of installation height for CPU air coolers, which can be extended to 168 mm by removing the side fan bracket. The case is compatible with both SFX and ATX power supplies, provided the ATX power supply does not exceed a length of 140 mm.

Thermal management is ensured by a flexible cooling concept. The case comes with two pre-installed 120-mm slim fans on a removable mount. For users who opt for liquid cooling, the case supports side-mounted radiators up to 360 mm in size when used with an SFX power supply, or up to 240 mm when used with an ATX power supply, provided the maximum thickness does not exceed 52 mm. An integrated, adjustable GPU support bracket is included to prevent sagging with heavier graphics cards.

Storage and Expansions

Storage options include a primary bay at the bottom of the case for either a 3.5-inch hard drive or a 2.5-inch SSD, with a second 2.5-inch SSD mount located at the front of the case.

For users who opt for the vertical tower orientation, Lian Li offers an optional Vertical AeroDeck. This accessory is designed to improve GPU cooling by allowing the installation of additional fans—up to three 120-mm or two 140-mm units. The AeroDeck includes tempered glass side panels and a magnetic PVC dust filter to keep the interior clean.

Prices and Availability

The B4-mATX has been available since June 26, 2026. The “Mesh” models cost €69.99/$69.99 in black and €74.99/$74.99 in white. The “Wood” editions cost €84.99/$84.99 in black and €89.99/$89.99 in white. The optional “Vertical AeroDeck” costs €29.99/$29.99.