Material and durability: Black matte material is sturdy and resists deformation, providing a durable mounting surface. Chassis mounting flexibility: The fixed chassis includes standard M3 coarsethread holes (8 screw holes) and standard power supply installation holes that support up/down orientation swapping for flexible configuration. Power supply positioning: Supports moving from the large power supply hole position to the small power supply hole position to accommodate different PSU sizes. Conversion rack for small PSUs: The small power supply panel is installed in the holeposition conversion rack of the large power supply chassis (black). Finish and compatibility: Black finish matches typical chassis aesthetics and hardware; designed to work with standard M3 hardware and common PSU mounting layouts. Practical applications: Industrial control cabinet: Allows flexible PSU sizing and easy reconfiguration without replacing the chassis. Compact electronics enclosure: Enables up/down swapping and holeposition conversion to fit different power supplies in limited space. Maintenance and upgrades: Facilitates upgrading or swapping PSUs by repositioning mounting holes and using the conversion rack for a secure fit.