My RLN36 (purchased May 2024) came with 3 small bags containing 5 screws each. I used 4 screws to mount one 3.5" SATA drive. This other page numbers each of the 3 SATA cables inside the NVR (with #1 on the left-side when viewing from the front). I am hoping more airflow could pass through the vents on the left and right sides of the NVR if I mount my one HDD in the center position ("HDD2"). (I have no thermal experience. I'm just guessing.) The NVR booted and operates just fine with a single HDD in the center position ("HDD2").