Resembling a rebreather apparatus, the Immune System Booster is an inhaler of which Ukkon could breath refined Imulsion into his bloodstream. Due to his biology as a Sire rather than a Locust, the Immune System Booster was a way for Ukkon to stabilize his mutated body and grant him benefits. The booster was also created by the Nedroma Health Institute as a way of treating Rustlung, but it had crippling side-effects upon those who used it.
As a Sire, Ukkon has a higher percentage of Imulsion mutation and crystallization of his body, making him somewhat resistant to the Imulsion's parasitic effects; like Myrrah but to a lesser degree. As such, the Immune System Booster - when breathed in - gifts Ukkon the ability to rapidly regenerate wounds that would kill any normal organism, extends his lifespan and increase his strength.
However, the effects of the Immune System Booster does not last long and Ukkon must find constant sources of refined Imulsion to restock his healing apparatus. The Immune System Booster is countered by Cytostatic Gas - a COG failsafe to render Ukkon's Immune System Booster impotent - with the gas blocking Ukkon's regenerative abilities and greatly weakening him.
Behind the Scenes
- It is possible that the design of the Immune System Booster was what influenced Ukkon in developing the Imulsion Injection Harness, to be used by the Disciples and Zealots.
- Model art was done by Paul Widelski. 
- Gears Tactics (First appearance)