Infinity (inf, or inf pu) is a Common Powerup. When applied to Standard Weapons, the weapon's ammunition will be set to its maximum and will no longer consume ammo when fired. You can only apply one Infinity per Weapon of Power. Infinity cannot be applied to Super Weapons or Atypical Weapons.
Infinity is considered an essential powerup, often sought out by players as soon as they begin. Any Standard WoP that a player plans on using should optimally be equipped with an Infinity, as it removes a player's reliance on ammunition: the most common impediment to clearing waves.