The b17 narrow imperial is another variation of our time honoured b17 design featuring a distinctive cut out section in the top of the leather first conceived and registered by brooks over a century ago in the catalogue of jb brooks amp co dated 1890 a model called the b86 imperial with its unique registered cutting is described as a sure preventative to all perenial pressure another distinctive feature of the b17 narrow imperial are the perforations along the lower edge of the leathe