The P.E.S. (Pressurized External Suit) is a piece of equipment on the Zombies map Moon. It gives players the ability to survive in areas that are void of oxygen on the Moon. The helmet is in the equipment slot and is therefore removable. The P.E.S. is free to take and is right in front of the player after teleporting to the Moon. Because the P.E.S. is free, it can easily be transferred between itself and the Hacker. It is available in every Air Lock throughout the map. Without the P.E.S., the player can spend a maximum of 15 seconds in a vacuum before being downed. Neither the P.E.S nor Hacker will replace Claymores.
When putting the helmet on in first person, it looks exactly the same as the Gas Mask that Hudson puts on in "Rebirth", despite the helmet looking different in third person.
While wearing the P.E.S., the player is unaffected by the Phasing Zombie' gas, but will still be affected by the explosion of the Phasing Zombie.
The player can receive infinite suits from one location, despite only one being seen.
If the player enters an area with no oxygen, the suit says: "Please activate P.E.S. Critical oxygen levels detected." After the player puts the suit on, it says: "P.E.S. active."
When the host puts on the P.E.S on for the first time in match, it will say "P.E.S activated. Welcome to Griffen Station. Artificial gravity and life support systems are offline."
The player can still drink perk-a-colas while wearing the helmet.
There is no reflection on the P.E.S. visor; it only shows a landscape on the moon, no matter where the player is.
Some characters will call the device "pies" because "P.E.S." somewhat resembles the word "pies".
A possible example of the beforementioned fact is Richtofen's quote when starting a game: "Oh, this must be the place where they bake all the apple pies!"
Players can put on the P.E.S. in three different ways. A player can put it on while standing, which is the regular way of putting it on. If crouching the player can notice that they are putting the P.E.S on slightly to the left. When putting the P.E.S on while prone, the player will put it on left.
When the helmet is on, the player can hear other characters speaking as if they were right next to them. This is likely because the helmet contains a walkie talkie.