Primary Focusing Coils is a technology that can be researched at the War Center in Tech Level 2. It costs 100 Food, and gives +1 attack to all Mech Factory and Troop Center units, except the Anti-Air Trooper. It must be researched before Cooling Sleeves becomes available.
This technology gives a modest improvement, and the fact that it affects so many units is a point in its favor.
"By researching this optimised blaster-firing mechanism, you grant your Troop Centre and Mech Factory units a bonus to their attack strength."