The Baby Play Kits and Play Gym complement each other, with very little overlap. Both are stage-based to promote baby's brain development. The Play Gym offers a whole year of play for foundational brain development, while the baby Play Kits target two-month blocks of development for deeper focus. The Play Gym and first year of Play Kits are meant to complement each other, so there are some important concepts (like the use of black and white high-contrast images) that are highlighted in both the Gym and in the first Play Kit in particular, but in different ways (so a rattle, a special first book, etc.). Furthermore, we know that many of our parents like to have playthings specifically for use with The Play Gym as opposed to a set to put in the diaper bag, take to grandma's house, etc. But we know that every baby plays differently and that needs differ depending on lifestyle.