This science kit starts out as a great looking detailed small heart anatomy model. When placed in water over the course of days it demonstrates the super water absorbing properties of polymers as it becomes a big heart. Just place the heart in water and it will grow many times larger. Great for Halloween party decor or party favors All in a heart stopping 5.25x2.5x2.5" box POS display holds 12 units For ages 8 and up Funny Christmas gift, if your Grinch's heart is two sizes too small, watch it grow three sizes! Fun science activity for homeschool, back to school, summer. Perfect for birthday gift bags, stocking stuffers, or any time you need a little STEM.