A compressed folder format. To access the .NSP file inside, you would need extraction software like WinRAR or 7-Zip . Legal and Safety Risks
Files from unauthorized sources are frequently used to distribute malware or viruses that can infect your computer or console. PowerWash Simulator (NSP)(DLC).rar
Using unauthorized files on a Nintendo Switch can lead to a permanent ban from Nintendo Switch Online services or render the console unplayable. Official Alternatives A compressed folder format
Playing Nintendo Switch Games: OSC Emulators & NSP Files - Ftp PowerWash Simulator (NSP)(DLC).rar
Distributing or downloading copyrighted game files without purchase is considered copyright infringement and is illegal in most jurisdictions.