Sizing Kits really help our customers who... 1. Have never tried custom press on nails before, 2. Are not sure if our shapes & lengths will fit them, or 3. Want to collaborate with us for a press on nail set. Review our universal nail lengths/sizes chart. Pick your nail length, and then shape. We have Extra Short, Short, Medium, Long, Extra Long, Kids, & Toe nail sizes. We also have Almond, Square, Coffin, Round, Stiletto, Kids, & Toe nail shapes!:)