- Broad Compatibility: A21 supports up to 360 mm radiators, graphics cards up to 380 mm in length and CPU air coolers up to 165 mm in height.
- Capable Cooling: The front-panel mesh is 40% porous to maximize the balance of airflow, dust filtering and RGB visibility.
- Ample cable management: The A21 provides a compartment behind the motherboard that is 33 mm wide to keep your wiring tucked away and tidy.
![AP201 Compact Space, Powerful Performance](https://dlcdnwebimgs.asus.com/files/media/a8b0646d-09f6-4032-a9d0-bd53fed9ca8a/v1/video/ASUS-A21.jpg)
ASUS
A21 Case
Discover Hidden Potential
The ASUS A21 is a PC case crafted for minimalist mainstream DIY PC builders, with support for a variety of AIO coolers and graphics cards, and plenty of airflow potential to keep things running smoothly.
Broad Compatibility
Despite being a micro-ATX case, the A21 still supports up to 360 mm radiators, graphics cards up to 380 mm in length and CPU air coolers up to 165 mm in height, giving builders plenty of options to assemble their next PC.
![ASUS A21 PC build](https://dlcdnwebimgs.asus.com/files/media/a8b0646d-09f6-4032-a9d0-bd53fed9ca8a/v1/img/ASUS-A21-compatibillty.png)
![highlight on the ROG 360 mm all-in-one cooler](https://dlcdnwebimgs.asus.com/files/media/a8b0646d-09f6-4032-a9d0-bd53fed9ca8a/v1/img/ASUS-A21-compatibillty-radiator.png)
![highlight on the ROG Strix RTX 40 series graphics card](https://dlcdnwebimgs.asus.com/files/media/a8b0646d-09f6-4032-a9d0-bd53fed9ca8a/v1/img/ASUS-A21-compatibillty-graphicscard.png)
![glass side panel of the ASUS A21 PC case](https://dlcdnwebimgs.asus.com/files/media/a8b0646d-09f6-4032-a9d0-bd53fed9ca8a/v1/img/ASUS-A21-compatibillty-glass.png)
Support
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360mm
Radiator
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380mm
Graphics Card Length
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165mm
CPU Cooler Height
Capable Cooling
The front-panel mesh of the A21 is 40% porous to maximize the balance of airflow and RGB visibility. Users can add up to three 120 mm fans to this section of their build to solidly manage system temperatures.
![Front angle of the ASUS A21 PC build featuring three 120 mm fans](https://dlcdnwebimgs.asus.com/files/media/a8b0646d-09f6-4032-a9d0-bd53fed9ca8a/v1/img/ASUS-A21-cooling.png)
40 % porosity
Ample Cable Management
The A21 provides a compartment behind the motherboard that is 33 mm wide to help you keep your wiring tucked away and tidy.
![Rear side of the ASUS A21 PC Case without side panel](https://dlcdnwebimgs.asus.com/files/media/a8b0646d-09f6-4032-a9d0-bd53fed9ca8a/v1/img/ASUS-A21-cable.png)
![highlight on the 33 mm wide cable management space of ASUS A21 PC Case](https://dlcdnwebimgs.asus.com/files/media/a8b0646d-09f6-4032-a9d0-bd53fed9ca8a/v1/img/cable-management-space-width.png)
Color-Coordinated Builds
Both variants of the A21 come with color-coordinated black or white internal I/O cables to compliment your build theme.