In one episode of Beavis and Butt-head from the 1990s, they are out back at a gas station. There is a vending machine with a bathroom door on each side of it marked "MEN" and "WOMEN".

A woman comes walking (supposedly from the gas station's store area) carrying a key which has a huge, clunky, metallic thing hanging from it. She stops at the door marked "WOMEN", unlocks it with the key and leaves the huge thing hanging in the door on the outside as she enters the bathroom.

I understand that the bathrooms are probably locked in order to discourage homeless people from sheltering in there, and to require some sort of "permission" to use them, meaning the key, but my questions are:

  1. Why does the key have such a large thing hanging from it?
  2. If the customer/bathroom user leaves it like that on the outside, doesn't that mean that somebody else can just open the door while she is in there? Or does it separately lock from the inside? Is this how it was/is actually done in reality?

I'm making the assumption that this "background detail" is based on reality, which is usually the case in this animated show's universe. Typically, it's just the main guys who are stupid, but anything that happens around them tends to be "how it really is".


  • 3
    We can probably assume a bolt or similar on the inside. The vast majority of such facilities I've used (on 4 continents) have had a privacy lock, regardless of key access (and independent of it if there is a key). The privacy lock also stops the cleaner walking in on you. Commented Sep 17, 2021 at 10:18
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    I think that's a car muffler.
    – mkennedy
    Commented Sep 17, 2021 at 15:06
  • 2
    @mkennedy - absolutely (although being British, I'd call it a rear silencer).
    – Spratty
    Commented Sep 17, 2021 at 15:14
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    No, you wouldn't normally leave them outside, that's weird. Commented Sep 17, 2021 at 18:55
  • 2
    Like @AzorAhai-him- said. Usually you get the key from the cashier to open the bathroom and then return it to them when you are done. In this scene, it looks like the key was left in the lock, probably just because it's funny. The detail here is somewhat based on reality, but there is an element of exaggeration going on here for comedic effect.
    – Seth R
    Commented Sep 17, 2021 at 19:11

6 Answers 6


So that people don't forget them in their pocket and leave the gas station with the key.

  • 52
    There are plenty of other places where this large reminder keyring is true as well. I'm familiar with outdoor activity centres using large floating attachments on the keys in case they get dropped in the lake despite being cumbersome. In general it should be too big to fit in a reasonable pocket. I've even seen hotels do it (the sort that want you to leave the key at reception when you go out, which seems to correlate with slow service at reception) Commented Sep 17, 2021 at 10:16
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    My local examination test centre has gigantic key fobs. It's to stop you forgetting to empty your locker when you leave
    – Valorum
    Commented Sep 17, 2021 at 18:30
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    @AustinHemmelgarn, it may depend on location but I have used many a hotel key whi h came with a street door key. Or mayby the size of the hotel, as small hotels do not bother with 24 hour desks and programmable electronic keys.
    – Willeke
    Commented Sep 18, 2021 at 5:18
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    @Austin you always need to leave the key when you check out, of course, but only some want the key left when you go out for the day. Many years ago this was the norm, and I'm more likely to choose modern and/or budget hotels when it's up to me. Commented Sep 18, 2021 at 9:20
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    Extension: since this is a service station/fueling bowser, a customer might be hundreds of kilometres away before they realise the key is still in their pocket, AND they might not be intending to return the same route. It may be tempting to throw the key away rather than do the right thing and return it.
    – Criggie
    Commented Sep 18, 2021 at 22:13

These are very common in the US, I've usually seen them as a large wooden block, roughly 1"x3"x12". Note, the one in the Beavis & Butthead clip posted looks like an old muffler, probably as a gag; I've never seen a real one made of a muffler. Also, at least the ones I've used, you generally take the key in with you, because, as you say, someone could come along and steal it. These restrooms do often have deadbolts inside too (and sometimes they don't. Hard drug use in gas station restrooms isn't uncommon and emergency services will need to get in if someone ODs in there).

Also, this kind of key is less common than it was in the 20th century, as most newer stations are built with bigger restrooms to accommodate multiple people at once, rather than the single-occupancy ones this kind of key is for.

  • 1
    Plus the use of keypad locks instead of keyed locks is common now in fast food places, etc.
    – davidbak
    Commented Sep 17, 2021 at 20:16
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    By a large wooden block, you mean like this from a Simpson episode? aht.li/3646975/simpson_gas_station_toilet_key.jpg
    – Clockwork
    Commented Sep 17, 2021 at 20:31
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    Your answer doesn't actually address the question of why such keyring attachments are used, though it provides a lot of other relevant information; presumably it's the same reasoning mentioned in the other answers. You should edit the post to independently answer the question. :)
    – V2Blast
    Commented Sep 17, 2021 at 23:37
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    Also of note, modern (21st century) gas station/convenience stores have entrances to the bathrooms inside the store area. The key is only necessary for a bathroom that has a direct entrance to the outside because these couldn't be easily/conveniently monitored by the cashier. (Don't forget - live CC TV monitoring was far more rare in the US prior to 2000 or so.)
    – FreeMan
    Commented Sep 18, 2021 at 13:41
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    If writing for someone not in the USA, it might be kind to convert the inches to metric "3cm x 8cm x 30cm"
    – James K
    Commented Sep 18, 2021 at 15:49

With objects such as keys or pens that people can easily absentmindedly forget they are holding and walk off with, something is often attached to them to make that more difficult. This being a cartoon, this is exaggerated both for comic effect and because smaller details are harder to draw.


We used a 1970 Pontiac 350 alternator adjustment bracket for the bathroom key return device. Just large enough to prevent disappearance by accidental pocket storage but light enough to be easy to carry.

Our restrooms were clean enough to eat off the floors being a "Full Service Station" with 24 employees, so customers would remark that our restrooms were cleaner that their bathrooms at home.

The station down the street had a 10 pound disc brake rotor attached to a chain to his key, however you did not want to use that restroom unless there was no other choice, it was a pig sty, as was the rest of the station.

  • cool, so automobile parts are sometimes used to bulk-up loan keys.
    – Jasen
    Commented Sep 19, 2021 at 4:53

The episode was a more a joke than need be. Gas stations that offer restrooms, often incorporated the key with a huge weight or silly object. One to deter theft of key. Also key is property of station so prevent it being lost by being easily distinguished so you don't accidentally take it with you when you leave. Modern gas stations avoid this, often having open rest rooms which shut with those rolling screens you see at malls.


One of the reasons they have a big "thing" attached to the key is so you don't lose it. With something as big as a small cat, it would be hard to lose. Another reason is to prevent theft of the key. You can't shove a key attached to some big "thing" into your pocket so you will be forced to carry the key. And when someone sees you carrying a key attached to the "thing", they will know immediately that you were the person that stole the bathroom keys.

Also, I wrote "thing" because I didn't know what the metal thing was.

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