I am an exclusive pumping mama, and I originally purchased these for my silicone cups, but at night I use my spectra plastic flanges while my cups dry for the next day. Curiosity struck and I wanted to try these insert in my plastic flanges, WHAT A GAME CHANGER!
I put them inside a 24 mm flange, and they fit perfect. They are flush to the rim of the flange, do not move around, and provide optimal comfort while pumping on those terrible plastic flanges. I don’t pump without these now - I will never go back.
Also, if you have elastic tissue, these work wonders in preventing your nipples from hitting the end of the flange!