MGI(Mobile defense Unit) the need for a mech that fills the role for front line defense unit was a necessity in troops on the ground. the sword 2 lack the armor protection to be an effective front line combat unit so the result was the development of the shield. the shield was the 1st mech in the federation to be equip with a portable nanite shielding generator. with a effective radius of 20 meters it can deflect attacks coming from a 50cal round to a 20in main laser canon(but not advisable)