As mentioned in the video, almost all standard single sleeping pads can be used with this design. Mummy-style designs do work best, but others can definitely be accommodated. 25" width (larger pad) is a more snug fit, and pad thickness plays a role too. In certain situations a thicker pad (2"+) could just mean a more snug fit when fully integrated. As seen, a goal of the design was to encompass as many pad options as possible.