two-sided

Short definition from Wiktionary

Adjective

1. 1
   Having two sides, bilateral.
2. 2
   Reversible.
3. 3
   Whose salient properties apply when (the specified object) appears on either side of a given binary operator.
4. 4
   Having two aspects or viewpoints.
5. 5
   That is necessarily or absolutely different than the respective coordinate alethic or temporal modality as well as its opposite.