Chaff Launchers
Codex: Adeptus Mechanicus, p. 7
A model equipped with this Wargear can set to deploy Chaff instead of setting to 8.1.1 - Overwatch. Until the start of its next turn, the model gains 5+ Cover Save. The Cover save is increased to 4+ against 'Missile' weapons. This includes any weapons listed under the 'Missile' category of the weapon section in their codex.