Seat is fully contoured to fit the human form. The plan calls for weather-resistant mahogany and sturdy white oak for use outdoors, but cedar would also do nicely. Though the width is easy to adjust, the plan calls for the rocker to be 48" wide. You will get full size patterns for all curved pieces, such as the rockers, plus a full list of the materials you need, instructions for building, and measured drawings with exploded diagram for easy comprehension of the construction of the piece.