Models : - Lo back (small) : BCWL-7210S - Lo back (medium) : BCWL-7310M - Lo back (large) : BCWL-7410L - Hi back (small) : BCWH-7610S - Hi back (medium) : BCWH-7710M Made of Medical Grade PVC, the Contour Wrap-Around Back Support is a great option for a small child with mild positioning needs, whether bathing or just simply sitting on the floor. Padded and available in two options, Lo-Back and Hi-Back, both include a harness for additional trunk support (Lo-Back = 2 point harness, Hi-Back= 4 point harness).