Spectra Spare Parts/Accessories Silicone Massager Insert (1 piece) is a malleable silicon insert that sits inside the shield to serve as a cushions for the breast, making expressing more comfortable. Soft petal design on the silicone, helps to massage the breast tissue, encouraging milk flow. Malleable silicon insert sits inside the shield to serve as a cushions for the breast, making expressing more comfortable. Soft petal design on the silicone, helps to massage the breast tissue, encouraging milk flow. Recommended to use with 28mm Spectra breast flange as a reducing insert if flange is too large This massager best fit 28mm flange. For 24mm and 32mm, the massager can sit in the funnel.