Goldilocks never pumped milk as far as we know, but she would have found the perfect flange! "Too Little, Too Big, and... Just Right" is helpful when YOU are selecting a Pump Flange. Download the FITS flange Fitting Guide for more details. Pinch your nipple gently to firm it up. Measure the tip of each nipple. Measure edge to edge near the tip. DO NOT MEASURE THE BASE Using the tip size number as the middle number, select your Goldilocks Kit. Select a Base Connector that matches your pump You will receive 3 Half Flanges - one of each size. Half Flanges are compatible with Medela and Lansinoh Pumps that use half flanges. For Spectra and Ameda, you will need an appropriate base connector. (Base Connectors)