For the purpose of accuracy we recommend you follow the process without the presence of a saddle pad.STEP 1) Place the saddle in the riding position on your horse/pony’s back and make a point of reference directly underneath the saddle nail – we suggest carefully parting your horses hair as a marker.STEP 2) Remove the saddle. Place the PE Gullet Gauge over your horse’s wither, aligning the gauge with the reference point that you made earlier.STEP 3) Ensure the gauge’s bearing area is lying comfortably against the horse. Ensure the gauge is clear of the horse’s wither.STEP 4) The tool will now indicate the correct coloured gullet for your horse in the PE Interchangeable Gullet range.We recommend repeating this procedure every three to four months.We recommend consulting a qualified saddle fitter when adjusting the fit of your saddle.