Spectra Silicone Massager. For use with the Spectra range of breastshields and breast pumps, these Silicone Massagers can be inserted into the funnels just before expressing to help cushion and massage the breasts, hence stimulating the milk ducts around the areola and breasts to increase milk flow and stimulating an earlier let down. Only fits 24mm and 28mm shields. Note: 24mm becomes 22.5 and 28mm becomes 26.5 with the massager attached. Includes one (1) Massager Insert for 24mm and 28mm shields only. If you are double pumping, you will need to buy two.