Express, gently and efficiently. The Optiflow active breast massage insert is made of pure silicone which gently, but actively, massages the areola. This effect stimulates the milk ejection reflex for a comfortable and efficient expressing experience. 2 Optiflow 26 mm Massage Inserts fit Ardo Breast Shells. Works with the Ardo Caypso or Carum Pumps. Made in Switzerland.