Plus-Plus is a whole new class of construction toy! One simple shape contains endless possibilities and hours of fun. Each piece easily connects to the next and lets your imagination create colorful flat mosaics or work in 3-D to make more intricate builds. Even curves are possible thanks to the unique design of this deceptively simple shape! A perfect STEM toy to develop fine motor skills, focus and patience - as well as design, imagination and creativity! All Plus-Plus sets are compatible with each other and this open play set adds more pieces and colors to the collection for more possibilities and fun. This 3,600 piece set comes with a mix of all Basic, Neon and Pastel colors, 21 colors in all. Also includes a reusable storage tub an Idea Guide Booklet for building. BPA-free and phthalate-free. Designed and made in Denmark.