Can the case support larger graphics cards, and what is the maximum GPU length it can accommodate?

Yes, the case supports graphics cards up to 400mm in length.

Questions & Answers: Cougar ARGB MidTower E-ATX Gaming Computer Case , Support 360mm Water Cooling ,Aluminum Tempered Glass Side ,Gen-2 Type-C USB 3.0 PC Case

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Cougar ARGB MidTower E-ATX Gaming Computer Case , Support 360mm Water Cooling ,Aluminum Tempered Glass Side ,Gen-2 Type-C USB 3.0 PC Case

High quality Mid-tower case, aluminum drawing process.
Built-in light controller and light control keys can be used with motherboard-compatible 5V ARGB connection.
USB 3.1 Gen-2 Type-C and dual USB 3.0 ports.
Toughened glass left panel without perforated metal-clad toughened glass.
Scientific duct design can let the air flow well: take away the heat quickly.
Supports two HDDS and two SSDS at the same time.
Excellent support for 400mm long graphics card and E-ATX motherboard, brings freedom for hardware system installation, front panel installation 360 water-cooled vertical graphics card maximum support :55mm (thick) x 350mm (long).
Disassembling and installing dust-proof heat distribution nets in multiple parts of the chassis without tools is convenient for cleaning and keeps the chassis away from dust.