The M990 Electrothermal-Chemical Smoothbore Cannon is a United Nations Space Command armament that is mounted on the M820 Main Battle Tank. Introduced into service in 2557, the M990 ETCSB cannon fires guided 150mm rounds with energized propellants.
Appearances[edit | edit source]
- Halo 5: Guardians (First appearance)
Sources[edit | edit source]