He selected the front door key from the two on the ring, and opened up.

"Forgot their front door key so came in through the back."

The door key didn't work and I was forced to drive a long way back to the office.

A door key on a string which can be reached through a letter box.

This was the door key they were passing up to him.

He gave me the front door key and I let us in.

Then what about a door key, the old-fashioned sort, quite big.

It has to be connected with the front door key.

He paid the driver, got out his door key, and entered the house.

I didn't say anything about the door key, but he took it.