The [exo_playback_speeds array](https://github.com/google/ExoPlayer/blob/r2.16.1/library/ui/src/main/res/values/arrays.xml#L28-L36) contains values with hardcoded [decimal separator](https://en.wikipedia.org/wiki/Decimal_separator) (`.`). When I have my device set to Czech language (and therefore to Czech locale), I would expect to see values like `1,5x` (instead of `1.5x`). While it's probably clear to users from the context, in Czech locale `1.5x` would meant _1500 times_. Other apps like YouTube and Files by Google use the localized values. EDIT: YouTube also uses actual [multiplication sign](https://en.wikipedia.org/wiki/Multiplication_sign) `×` instead of the latin letter `x`.