The 6521 micro case uses a top-mounted ATX PSU and supports Micro-ATX and Mini-ITX motherboards. In a 325x170x350mm body, it offers a 5.25 inch ODD bay, three SSD bays, and an optional Type-C (2.0/3.0)—a practical choice with flexible I/O.

• Rugged Platform: 0.4mm SPCC/SGCC steel, top-mounted ATX PSU, ABS front with metal top and dual metal side panels, Micro-ATX/Mini-ITX support, and a 325x170x350mm body and 3kg net weight.
• ODD and Storage: One external 5.25 inch ODD and one 3.5 inch bay, plus internal 1x3.5 inch HDD and 3x2.5 inch SSD bays.
• Practical I/O: Power and reset buttons, two USB ports, and HD audio, with optional Type-C (2.0/3.0).
• Four Slots and Cooling: Four expansion slots, front 2x120/92/80mm, rear 92/80, and left 120mm fan mounts (fans optional); GPUs up to 295mm, CPU coolers up to 140mm.
• Security and OEM: Kensington lock, padlock loop, and alarm switch with an optional electronic lock; full OEM customization.