Lian Li B4 Mesh mATX Mini Tower Case – Compact 21.3L with 360mm Radiator Support

The Lian Li B4 Mesh is a compact mATX mini tower case co-developed with Daniel Hansen of DAN Cases, combining modular flexibility with precision steel construction in a 21.3-litre volume. Despite its small footprint, the B4 Mesh delivers a surprisingly wide hardware compatibility window, making it a strong choice for builders who want a capable, tightly packaged system without sacrificing upgrade headroom. The case supports Micro-ATX and Mini-ITX motherboards and accommodates graphics cards up to 358mm long across up to 4 expansion slots. A pre-installed anti-sag bracket adds structural support for heavier GPUs. A removable front fan bracket allows large graphics cards to slide in from the front of the chassis, easing an installation step that can be awkward in compact enclosures. Bottom fan clearance depends on GPU thickness: 2.5-slot cards allow standard 25mm fans, 3-slot cards allow 15mm slim fans, and cards thicker than 3.5 slots do not support bottom fans. Cooling flexibility is a core strength. With an SFX PSU installed, the side panel supports 360mm, 280mm, and 240mm radiators up to 52mm combined thickness. With an ATX PSU (up to 140mm length), side radiator support narrows to 240mm. CPU air coolers up to 168mm tall are supported; installing the side fan bracket reduces that clearance to 162mm. The top houses two pre-installed 120×120×15mm slim fans running up to 1800 RPM and daisy-chained for reduced cable clutter. In total, up to nine fans can be fitted across the top, side, bottom, rear, and front positions. The rotatable AC power inlet accommodates both horizontal desktop and vertical standing orientations. The reversible rear fan bracket can face outward to create additional liquid-cooling clearance or inward to improve air-cooler performance. A removable top fan bracket simplifies CPU 8-pin cable routing. Tool-less removable panels and a removable bottom dust filter round out the modular, maintenance-friendly design. The front I/O panel provides a USB 3.2 Gen 2 Type-C port (up to 20 Gbps), a USB 3.0 Type-A port, audio jacks, and a power button. Verified Specifications: • Dimensions (D×W×H): 420 × 191 × 288 mm • Volume: 21.3 litres • Motherboard support: Micro-ATX, Mini-ITX (no back-connect) • Max GPU length: 358mm (4-slot) • Max CPU cooler height: 168mm (162mm with side fan bracket) • PSU support: ATX up to 140mm / SFX • Radiator support (SFX PSU): 360mm / 280mm / 240mm (side); (ATX PSU): 240mm (side) • Pre-installed fans: 2 × 120×120×15mm slim (top, up to 1800 RPM) • Max fan support: 9 • Storage: 1× 2.5" SSD (front), 1× 3.5" HDD or 1× 2.5" SSD (bottom) • Expansion slots: 4 • Dust filter: Bottom • I/O: USB 3.2 Gen 2 Type-C (20 Gbps), USB 3.0 Type-A, audio, power button • Material: Steel • Colour: Black • Warranty: 1 Year • SKU: G99-B4X-IN