LIAN LI Unveils B4-mATX: Compact MicroATX Case with Versatile Orientation
LIAN LI Industrial Co. Ltd., renowned for its innovative PC cases and components, has introduced the B4-mATX, a 21.3-liter small form factor chassis developed in collaboration with DAN Cases. This new case is engineered to maximize hardware compatibility within a compact footprint, supporting microATX motherboards, graphics cards up to 358 mm in length, and both ATX and SFX power supplies. The B4-mATX offers flexible positioning, functioning as either a horizontal desktop unit or a vertical tower that reduces desk space usage by 30%. With a choice of mesh or real wood front panels in black or white, the B4-mATX caters to both high-performance and lifestyle PC builds.
Dual Orientation for Flexible Desk Placement
The B4-mATX is designed for adaptability, allowing users to position the chassis horizontally for a traditional desktop look or vertically to save valuable workspace. A rotatable AC inlet ensures convenient cable management in both orientations—rotating outward for easy access in horizontal mode or inward in vertical mode to neatly store excess cable length inside the case. Additionally, a swiveling cable bracket beneath the PCIe slots keeps rear I/O and power cables flush with the chassis in vertical setups, accommodating connectors up to 52 mm tall. The front panel is available in either perforated mesh for optimal airflow or real wood finishes (walnut or beech) for a premium aesthetic, with both options offered in black or white.
Flexible Cooling and Power Supply Support
The B4-mATX comes equipped with two pre-installed 120 x 120 x 15 mm slim non-RGB fans mounted on a removable bracket for exhaust. The front fan can be reversed to serve as an intake when paired with a CPU air cooler. The chassis includes dedicated mounting brackets for either an SFX or a 140 mm ATX power supply. When using an SFX PSU, the case supports side-mounted radiators up to 360 mm (with a maximum thickness of 52 mm). With a 140 mm ATX PSU, radiator support is up to 240 mm. A reversible rear fan bracket can swing inward to enhance airflow for tower-style CPU coolers or outward to provide clearance for a side-mounted all-in-one liquid cooler.
Compact Size, Full-Size Hardware Compatibility
Despite its modest 21.3-liter volume, the B4-mATX accommodates high-end components. It supports graphics cards up to 358 mm (14.1 inches) across four expansion slots and CPU air coolers up to 162 mm (6.4 inches) in height, or 168 mm (6.6 inches) with the side fan bracket removed. A vertically adjustable GPU anti-sag bracket is pre-installed, featuring an adjustable arm that supports the graphics card without obstructing its fans. Storage options include space for a single 3.5-inch HDD or 2.5-inch SSD at the bottom, plus an additional 2.5-inch SSD at the front.
Optional Vertical AeroDeck for Enhanced Airflow
For users building in vertical orientation, the optional B4-mATX Vertical AeroDeck accessory enhances cooling and aesthetics. The AeroDeck creates a direct airflow path to the GPU and increases fan capacity, supporting up to three 120 mm fans or two 140 mm fans. It features tempered glass side panels to showcase installed fans and a magnetic PVC dust filter for easy maintenance. The AeroDeck matches the real wood finishes of the B4-mATX Wood variants, available in walnut or beech, and comes in both black and white color options.
Availability and Pricing
The LIAN LI B4-mATX will be available starting June 26, 2026. Pricing is set at $69.99 / €69.99 for the Mesh Black version, $74.99 / €74.99 for Mesh White, $84.99 / €84.99 for Wood Black, and $89.99 / €89.99 for Wood White. The optional B4-mATX Vertical AeroDeck accessory will also be available on launch day for $29.99 / €29.99 in both black and white.
