Butterfly leggings come in many styles.  This product is made of thin cotton and has a slim fit, great for the Spring.  They run small.  The product in the photo is the color Riverside, sort of like denim blue but not heather is in the product photo here.  Leggings are great for layering a shirt over them.  For a thicker and warmer style look at the other style of Butterfly leggings on the website.

12-18 and 18-24  are months.  2-4 means 2-4 years old.