Set of 10 Chameleon dual-tipped alcohol markers in gently used condition. Designed to make color gradients and blending by infusing the pen nib with a colorless toning medium from a built-in chamber on the marker. Original retail price was $22-24.

To use these markers, you attach the mixing chamber to the nib (brush or bullet side) for 5-35 seconds while upright, then color immediately as the pigment transitions from light to dark.