: The .nm4 extension is a proprietary map format used by Navikey's 7 Ways software.
: An nm4.zip file is usually a container for one or more of these map files, allowing users to download entire regions or countries at once. nm4.zip
: Use a tool like 7-Zip or WinZip to extract the .nm4 file(s) from the zip archive. nm4.zip
Knowledge Base / FAQ: What is a ZIP file and how do I install a ... - ESI nm4.zip
: Copy the extracted .nm4 files directly into that maps folder.