The Aerocool M40 has a the Micro-ATX form factor. Micro-ATX is a smaller version of the ATX standard which is designed to make your case and the system therein lightweight and portable. Using the Micro-ATX standard, the case can house motherboards and power supplies with form factors Array. The dimensions of the case itself (LxWxH) are 380mm x 295mm x 233mm.

The Aerocool M40 has four expansion slots, so there is some room for extra components, which may be a deciding factor when planning on the longevity and build type of a PC system. Installation of hard drives into these drive bays is made all the more easier by screwless rails that allow tool-less mounting.

Made primarily of Steel, the Aerocool M40 is built to be strong and well-ventilated. Steel cases are generally fairly cheap and sturdy, but also tend to be quite heavy. Whatever your case's material, it is important to keep a consistent airflow so that heat doesn't build up inside. It is therefore advised that you make use of the available built-in case fans and fan installation sections.