This body armor was made after Lolman Sticklimbs noticed the conventional helmet and vest proved inadequate against the pet pet soldiers and their guns. But it's not perfect. One flaw is that it's really heavy. Lots of weight leads to moving really slow. Slow movement lets machine gun fire mow you down. Another is being easily noticed. However, this was combatted by Lolman introducing camoflauge variants. Yet another is that is was designed with Scratch Cats in mind, and not other forms of soldier. This meant that non-cats had to deal with the helmet and vest.
