From the Manufacturer:
This pack contains neon blue, neon green, neon yellow, neon orange, neon pink, and neon purple. Paint with color wax pucks. This medium, dries in seconds, is less expensive than oil paints, is eco-friendly and achieves oil painting effects! simply Dip the tip of the Cray-Pen into the wax puck and apply to your surface for endless creativity.
The Cray-Pen is a wallet-friendly alternative to oil paints and encaustics.
Just heat up the tool, dip the hot metal tip in wax, and gently touch the tip to your painting surface — it works with most plastic, wood, canvas, glass, metal, and paper. No solvents needed.