Contagion is an Indie, cooperative, multiplayer, Source-based, zombie survival horror, first person shooter PC Game developed and published by Monochrome LLC.
Re-skinned the fist aid kit, since getting randomly swiped at by corpses doesn't really hurt, the big worry is the infection, this skin indicates that it holds an experimental temporary vaccine.
DISCLAIMER; I don't know if the first aid kit stops the infection or not, this is merely a visual change.