The combo trundle unit consists of both a linkspring and pop-up trundle along with tubular arms. This is the ideal replacement for an existing daybed, you can take the daybed frame off and use the trundle arms in its place. The simple styling of the trundle arms make this a perfect solution for any small bedroom space and at an economical price. The pop-up trundle unit is constructed with your loved ones safety in mind. Gravity locks prevent inadvertent release, while specially designed tension spring tabs help to lock the activation bar securely in place.