Can I use my own mattress, or is a special one needed?

This would depend on the style of mattress you are currently using, but in most cases yes. Wall beds keep your mattress in a vertical position most of the time and as such, the mattress should be able to generally hold its shape when stood on end.  A mattress that is able to do this is less likely to droop or sag within the frame. Adjustable straps can be found at each corner of the mechanism to hold the mattress in place and minimize such a possibility, but this ensures a comfortable sleep surface, prevents unwanted pressure on the frame, and ensures the mechanism and panels can transition properly. Above all, ensure that the mattress dimensions and weight are within the range outlined below: