two single beds, turn into double

I saw a single bed on the web a while ago that has another single bed that goes underneath it. You can pull out the underneath bed which is then another single bed, but the two go together to make a double.

I'm looking for one of these and haven't a clue what to call it, so can't google it! Anyone know?

(I know the description isn't great but too tired to think more....)

I have one of these, they're called a guestbed/rollaway bed

Forgot to say where I got mine.. Argos!

Thats like my one. Quick search so I brought up the UK Argos but can't be bothered looking for the Irish version.

We have the Argos one - very handy and space saving - only thing is when DH's parents were staying - daddy in law moved too quickly in the bed and fell between the two - better not go there!!!

well daddy in law should stay on his own side ! - and keep away from mammy in law when they are guests in other people's houses !!!!!! - better put up a warning sign like one of those you see at swimming pools, no this, no that ! - this bed is not suitable for the following activities !