12,5" - a really good size that is suitable for days of "heavy flow" All materials are 100 percent cotton but provide a really good protection . Night Pads are extra padded on the sides for a better night sleep. Of course it is best to presoak them in cold water before washing them on COLD. Maintenance is pretty easy and self-explanatory. Presoak with soap in lukewarm water and wring it until the water runs clear. later, wash on cold, dryer safe MATERIAL - 100 percent Cotton.