The In Win BL640 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 365mm x 96mm x 330mm.

The In Win BL640 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. The case has one 5.25" drive bays, which is enough room for an optical drive but little else, and with just one 3.5" drive bay, there is basically no room at all for expansion. With one 2.5" bay, however, there is enough room for a laptop-sized HDD or solid-state drive.

Made primarily of Steel, the In Win BL640 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.