Chameleon Kids Blendy Pens are really four markers in one. Each Blendy Pen has two colors, one on each end. When you twist the pens, the colors meet in the middle Fusion Chamber, blend, and create two additional colors. All of the pen colors are bright and beautiful! For our review, we received two Large Chameleon Kidz Blendy Pen Kits. The Large Blendy Pen kits come with twenty Blendy Pens, ten Fusion Chambers, ten coloring Posters, two sheets of Stencils, and one Blendy Pen Airbrush. The Blendy Pen Airbrush adds another level of coloring fun. Simply apply a Blendy Pen to the Airbrush and blow into the chamber. This disperses the ink into the air and onto your paper. You can freestyle with the Airbrush or use one of the included Stencils, both are fun.