Using this ringtone format is easy and free at https://klingeltonkostenlos.de..../klingeltone-fur-wha You simply download the song from the internet, transfer it to your device and then set it as your ringtone.
This is the most popular ringtone format, with many users preferring it over mp4 or m4r. You can download a huge selection of ringtones in this format and they're all high quality, so you won't have to worry about lag or audio quality issues.