.DLO File Extension
File Type3ds Max Plug-in
What is a DLO file?
Plugin file used by Autodesk 3ds Max, a 3D modeling and animation program; adds new features to the software, such as importers or exporters for a third-party 3D file formats; enables users to customize software capabilities.
NOTE: Newer versions of 3ds Max use .DLU files for extensions.