Oh I only know they make baby motion flanges. Haven't heard about inserts
I just realized that I lied to you!!!! Omg! My inserts are by Freemie!!! I realized while washing. I also have Legendairy Milk inserts, but I do not like those as much at all.
I have the Lacteck inserts. The like silicone flange inserts. I got mine true to size. I’m about 21 mm and use the 21 insert in my 24mm flange! They have helped me so much and are my absolute fave!