"Stubby" key Euro cylinder

[SimonH2]

A while ago, while looking for something else, I came across a video on Youtube where someone was making a big deal of selling euro cylinders with "stubby" keys that can be left in without stopping the other side of the lock being used. so you can leave a key in the inside without locking anyone out.
So you can have the advantages of a thumbturn (by leavingva key in) but with the option of taking the key out to (for example) prevent little fingers unlocking a door.

But try as I.might, I can't find it again. Anyone know where I might find them ?

 

[Mottie]

I just pull our inside key back half an inch. That way the door can be unlocked from the outside but the key is in place if you need to get out quickly in the middle of the night in an emergency.

 

[SimonH2]

I know we can do that ... if we remember.
Having taken some cylinders apart for a look, there's no fundamental reason they have to be as they are - other than "that's how we've always done it"