A3 Romper Suit is a dynamic one-piece loose outfit. It was created by Aurora Smith for Aiko 3.
The download is in three parts: part 1 is the mesh, and parts 2 and 3 have four MATs each (for eight textures total).
This is Poser dynamic wardrobe; it cannot be used as-is in Daz Studio 3 or 4.0 through 4.10. There are, however, means by which you can drape in Studio 4.0 or higher using the paid VWD Cloth and Hair at Renderosity. If you have the dynamic plugin from Optitex for Studio, the paid DynCreator for DazStudio will take the clothing prop and convert it to something Optitex can work with. Daz Studio 4.11 introduced dForce, with which most Poser dynamic clothing items can be made to work by applying dForce surface settings. Some tweaking may be necessary.