The MB77 Personal Defence Weapon is a UNSC weapon used with the Wolf Armored Assault Suit. The weapon is essentially a oversized machine pistol with a magazine of 54 9.5mm rounds, the same ammunition fired by the BR09, mounted forward of the grip. The MB77 is intended for use as a backup weapon and, as such, is carried at the side of the Wolf AAS. It features a 4x digital scope with night vision capability.