M.2 drives generate a lot of heat, and thus fans are a requirement and can’t be disabled. It’s not that the fan is obnoxiously loud either way, but it’s definitely noticeable in a quiet room, and even more so when the enclosure is sitting in a vertical position. I recommend keeping the 4M2 resting in its horizontal position, because this causes the fan to face downward, helping to suppress some of its fan noise. Feet on the side and on the bottom of the unit allow it to rest horizontally or vertically depending on your preference. The unit sports a black exterior with perforated holes on the front panel to help facilitate air flow. Stack two 3.5-inch mechanical hard drives on top of each other, and you’ll get a rough idea of what it’s like to have the OWC Express 4M2 sitting on your desk. Because the drives are so small, the OWC Express 4M2 enclosure measures only 5.4 x 4.4 x 2.4-inches. As you can probably gather from those measurements, it doesn’t take a lot of real estate to house four M.2 drives. M.2 drives look almost like sticks of gum, measuring roughly 3-inches by less than an inch. Like those enclosures, the OWC Express 4M2 comes equipped with four drive bays, but the difference is the drive “bays” are super-tiny M.2 slots. After reviewing products with four 2.5- or 3.5-inch drive bays, I’m used to seeing larger storage enclosures like the CalDigit T4 or the Akitio Thunder3 Quad X. My first impression of the OWC Express 4M2 is that it’s really small.