What is an infertility kit

Two versions: Philter of Infertility (one use item) and Exceptional Infertility Kit (account locked, infinite use)

They're used to make a pet Infertile (unable to breed)
It cannot be undone
It is generally used by people who do projects, on project offspring (or Breedjects) they are selling, to prevent other people from stealing their work and profiting off of it/ undercutting their prices (since projects require a lot of time and dedication and Money to do) and protect the economy of max-stat projects and the like