This property defines the Unicodes which belongs to Modifier Tone Letters block
Characters like ꜀,꜁,꜂, etc. are listed under Modifier Tone Letters Block.
32 Characters are present in Modifier Tone Letters Block starting with the Unicode point U+A700 that represents the character ꜀.
Currently, as per latest version 15.0.0, Unicode supports 328 number of Block. Here are a few examples - Latin Extended E,Adlam,Aegean Numbers, etc.