Ameda flexishield areola stimulator, 21mm.The flexishield areolar stimulator mimics the baby's suckle to assist with "let down" for greater milk flow and volume.This soft, silicone insert fits inside the 25.0 mm ameda breast flange found in ameda hygienikit milk collection systems and joy, purely yours, finesse, platinum, elite, hygeia, lansinoh original double pump flanges, bailey nurture iii flanges and medela standard size breast shields and acts as a cushion and reducing insert.The gentle massaging action softens the feel of standard flanges while reducing the size to 21 mm for maximum effectiveness for smaller nipples.Buy two for double pumping.Bpa and dehp free product.