It is nice to see someone curious! I took a picture of my friend's wheelchair for this project and just got some information from them: Apparently this is a 'LT-700T Wheelchair'. They told me this specific design is built to be lightweight and easy to fold/store which does make it less comfortable. They said they purchased an extra cushion to go underneath for this reason. One thing I didn't know was that there are attachable leg cushions that I did not include in the drawing.