These red dwarfs have spectral types of L0 to L2. There is some overlap with the properties of brown dwarfs, since the most massive brown dwarfs at lower metallicity can be as hot as and have late M spectral types.

Definitions and usage of the term "red dwarf" vary by how inclusive they are on the hotter and more massive end. One definition is synonymous with stellar M dwarfs, yielding a maximum temperature of and . Another includes all stellar M-type