This is the key for our Renault Espace. It's credit-card-sized in area, but is about 6.5mm thick. What's annoying about it? It doesn't fit on a key ring.
That little hole at one end might look like it could be used for attaching a key ring, but that's the end that goes into the slot in the car. And being credit-card-sized, you might figure that you could keep it in your wallet, but I did that at first and the key lasted about a year before all the stresses and strains that my wallet suffers in daily use (I imagine), caused it to fail.
So now it lives a life detached from my key ring, and at any given time, I know where all my keys are except the one for Espace. Which gives rise to conversations like:
"Have you seen my Espace key?"
"No, you had it last, you drove to the shops"
"I'm sure it was on the hall table"
"No, that was last week."
"Are you sure you haven't picked it up by mistake"...
and so on, followed by a house-wide search, every time I want to take the effing thing out. I will not buy another car whose key doesn't fit on a key ring.
....... now I must remember that the key is in the scanner.