You've got it! A pop-up trundle does exactly what is says — pops up to create more space (or combine for a bigger bed). 1.A ...

long-lasting wooden or metal frames. Be sure to check if the trundle can accommodate a twin or trundle-size mattress (which is lower in height) to ensure the mattress you purchase fits. Daybeds ...

This list also contains trundle beds and convertible daybeds, which stow a second bed ... determines what kind of mattress it can contain. Metal pull-out mattresses are typically thinner, between ...