Pulowski Preservation shelter

Pulowski Preservation shelters are coin-operated, one-person fallout shelters found on street corners throughout the more urban areas of the Capital Wasteland and the Commonwealth, provided by Pulowski Preservation Services. Advertised as a "sensible" and "affordable" alternative to the Vaults, people would ostensibly use them as a last-minute resort in the event of a nuclear attack. The shelter itself is firmly secured to the ground, and ventilation piping is attached to the rear of the booth. Some models have luminous sign on the front of the shelter indicating whether or not it is occupied.

Pre-War use
Though the shelters can shield against explosive force, they do not seem to shield against radiation. It could be speculated that the installation of so many booths may be seen as a profiteering scheme in the climate of fear before the Great War began, or they may simply be in disrepair when found by the player character. The shelters only had an air supply, no food or water, so the occupant's survival was dependent on what they were carrying at the time. Whether any occupant survived through the use of these shelters is unknown, though many are filled with skeletons or feral ghouls, suggesting the majority of occupants died trapped inside. The last-minute nature of the booth meant that ill-prepared occupants were likely resigned to die from starvation if they survived the high radiation levels. Considering the blood splatters within several booths containing handguns, it seems that some occupants committed suicide after losing all hope of survival. The only advice offered after entering the booth is: "Wait for radiation to clear. Enjoy your stay." Although somewhat illogical, it seems these shelters were intended to be reusable; considering the tone of advertising the shelters were given, the risk and cost of nuclear devastation pre-War was likely greatly underestimated by the general public. It's possible that they were a scam of sorts, intended to cash in on panic and false alarms while not being able to keep occupants alive during a real nuclear event.

Post-War use
Though apparently coin operated, the player character can enter simply by pressing on the coin-slot (no money will be taken when pressing the coin slot). Two centuries later, Pulowski shelters have found new use in protecting citizens of the wasteland from its dangers; at least one non-player character (Bryan Wilks in "Those!") hides in a Pulowski shelter. Conversely, in Paradise Falls the shelters are used as punishment cells; a Pulowski shelter at the far end of the settlement is used to detain unruly slaves, and is named "The Box." This shelter is unique in that it has also been modified to be lockable, imprisoning the slave (in this case, Rory Maclaren). The key to this shelter is in the possession of Forty, typically nearby sitting on a bench or patrolling around the destroyed car wall.

Fallout 3
There are a total of 18 Pulowski preservation shelters located throughout the Capital Wasteland, including "The Box" at Paradise Falls, with a 19th being found in the same G.E.C.K. cell as the games intro. A normally inaccessible 20th shelter is added by the Point Lookout add-on.
 * 1) Arlington Cemetery South: contains a mannequin, two shot glasses, sexy sleepwear and wine.
 * 2) Arlington Library: Contains a skeleton with 10mm pistol, two boxes of 10mm rounds, and a Guns and Bullets.
 * 3) Chevy Chase: Contains one skeleton.
 * 4) Chevy Chase Metro: One frag mine in front of hatch, contains three bottles of purified water, a lead pipe and a teddy bear.
 * 5) Dupont Circle: Contains two skeletons, a stimpak a Vault-Tec lunchbox, and a .32 pistol.
 * 6) Falls Church: Contains a box of .32 caliber rounds, a box of 5mm rounds and two bottles of dirty water.
 * 7) Flooded metro: Contains one skeleton, a Chinese Army: Special Ops Training Manual, a pulse grenade and two stimpaks.
 * 8) Georgetown parking lot: Empty.
 * 9) Georgetown West: Contains five beers, three cherry bombs, a box of Fancy Lads Snack Cakes, a Nuka-Cola Quantum, some Railway spikes and a box of Sugar Bombs.
 * 10) Grayditch: Contains Bryan Wilks during the quest Those!
 * 11) Hubris Comics HQ: Contains a conductor, a Dean's Electronics, a hammer, a motorcycle gas tank and two wrenches. A mechanic possibly occupied this shelter.
 * 12) L'Enfant West: Contains a skeleton, a Big Book of Science, a bottle of wine and a pair of eyeglasses.
 * 13) Paradise Falls: Converted into "The Box" by slavers for solitary confinement, contains Rory Maclaren.
 * 14) Pennsylvania Avenue, east of Metro: Contains a deactivated protectron and a locked (Very Easy) ammunition box of small energy cells and two Stealth Boys.
 * 15) South of Rivet City: Empty.
 * 16) Takoma Park: Contains a recently dead wastelander with random chems and bobby pins, ammunition box with random ammunition.
 * 17) The Capitol building, outside the east exit: Contains a briefcase, a Lying, Congressional Style and four stacks of pre-War money.
 * 18) Vernon Square: Contains a skeleton, a radiation suit and Rad-X.
 * 19) One unreachable shelter glimpsed from the intro movie, the set for which is actually built in-game, has a pair of skeleton legs.
 * 20)  Pilgrim's Landing, on a rooftop in the boardwalk area. It is not meant to be encountered during normal play and can only be reached with console commands or through strategic jumping. Additionally, it cannot be opened, and was placed there for technical reasons, as it houses the non-player character The Brain. The Brain is a NPC that serves as the dialogue source for Professor Calvert when discouraging the player from deploying the cogwave jammer in the quest Thought Control.

Fallout 4

 * In Concord, to the north a short walk from the Museum of Freedom.
 * Near Trinity Tower.
 * 2 located at the C.I.T. ruins in the west of the C.I.T. rotunda building.
 * At the General Atomics Galleria, outside Panelli's Bakery. This contains a woman's skeleton and several bakery tickets.
 * Outside of the Corvega assembly plant. It contains a mini nuke.
 * Outside the D.B. Technical High School.
 * Outside College Square. It contains a feral ghoul.
 * 5 shelters in same place - south road from bridge to Beantown Brewery. Can be seen during Call to Arms quest.
 * 5 southeast of Graygarden
 * Near Bunker Hill, to the south, under an overpass. It contains a plastic pumpkin filled with bubblegum and other minor food items, toothbrush and baseball cap.
 * In Jamaica Plain, in front of the town hall.
 * Outside of Gunners plaza.
 * In Forest Grove Marsh, near the outskirts of the town.
 * Outside the Combat Zone next to the broken building. This one has a urinal in it.
 * Northeast of Eagle's Cove tannery: Contains a mannequin holding a camera.
 * Nuka-Cola bottling plant next to the shipping area outside: Contains Rad-X and a Nuka-Cola.
 * Two at the south edge of the Hubologist's camp.

Fallout 76

 * Four on a truck on Route 91, exactly on the number of the road on the map, right of relay tower HN-B1-12.
 * Three outside of Riverside Manor, each of which are secretly elevators. Closing the door while in one leads to the basement of Riverside Manor.
 * Three can be found behind the Seneca Rocks Visitor Center, near the weapons workbench.
 * Two behind The Whitespring station, near the tent.
 * One next to the Morgantown Station.

Fallout 3

 * Once the player character has closed the shelter door, no NPC will be able to open it.
 * While standing in the shelter, Bryan Wilks might ask "What's this funny suction hose for?" with no indication given to its purpose.
 * If the player character is under attack by fire ants while next to (or close to) Bryan Wilks while he is in the shelter, one can hear him complaining about the heat and wondering why it is so hot.
 * The fan in the back of the shelter only moves if the shelter is occupied.
 * Despite the sign telling users to "wait for the radiation to clear," there is no Geiger counter or any other form of radiation measurement, meaning that residents, if they had survived the other obvious problems, would have to guess at when they could leave.

Fallout 4

 * The shelters are a brighter shade of blue, and also feature pre-recorded ads for pre-War goods and services. They are also much larger, possibly allowing for one more person, and if there is enough space, possibly more. Unlike their Fallout 3 counterparts, they can apparently protect their occupants against explosions.
 * A Novice locked preservation shelter in College Square is occupied by a live feral ghoul. This further implies that the preservation shelters were ineffective at protection against radiation.
 * The shelters contain face masks and a fan, suggesting they had some form of ventilation.
 * Going inside one during a radiation storm still give the player character rads, suggesting that it indeed would have been ineffective against the fallout following the Great War.
 * Unlike in Fallout 3, non-player characters can now open a shelter as well.
 * The shelters will generate light when opened, potentially illuminating the player character for enemies in a dark area.

Behind the scenes
In Fallout 4 and Fallout 76, the Pulowski Preservation shelters are voiced by Elmarie Wendel.