SMG Heat Sink - Increases heat conductivity of thermal clip receiver. Negates heat generated by some shots.
SMG Magazine Upgrade - Increased magazine capacity means more shots, fewer reloads.
SMG Scope Upgrade - Simple 2x optical scope enchances stability while zoomed. Increases accuracy while moving and taking damage.
SMG Ultralight Materials - Superior lightweight alloys replace weapon parts, making weapon less obtrusive and easier to handle.