.M4R File Extension
File TypeiPhone Ringtone File
What is an M4R file?
Custom iPhone ringtone created with iTunes; can only be created from songs purchased from the iTunes music store that allow ringtone creation; automatically transferred to the iPhone when the phone is synced with the computer using Apple iTunes.
NOTE: M4R files created with third-party software programs or downloaded from the Internet may not include copy protection. These files may be played by other programs such as VLC media player.