As the player progresses further into Rapture, different types of ammunition become available. Quantities of some advanced types of ammo in a machine may be limited. Inventable ammo, such as Electric Gel and Trap Bolts, are not sold by the machines at all. The machine will show how much of each type of ammo is being carried by the player, and what the carrying limit is, so unlike the U-Invent machine, the risk of buying more than its limit is minor. (It is possible to be carrying near the limit and buy more than the limit. The excess will be left at the machine.) If the player is at the limit, the ammo will be grayed out in the machine's listing of ammo.