Molotow One4All markers are engineered and manufactured in Germany. Their high-quality, acrylic-based ink is permanent, UV resistant, quick-drying and non-toxic. It can be diluted with water or acetone, and will dry to an opaque, semi-gloss finish on nearly any porous or non-porous surface. They feature a patented capillary system and a Flowmaster valve, which offers a consistent paint flow to the tip of the marker. Suitable for both indoor and outdoor use. Use them with other Molotow spray paints and markers. Each marker can each be refilled at least 50 times using Molotow One4All Paint Refills, which can be mixed to create the colour of your choice. Tip: The numbers on the side of each marker (e.g. 127, 327, 427, 627) denote the size of the barrel, and thus the amount of paint the marker will hold. The Molotow One4All range is adaptable and environmentally friendly, as all markers are reusable and both the markers and the spray paints use the smallest amount of solvents possible, relying on an acrylic paint which is 85% water. The packaging is environmentally friendly and the manufacturer has a social responsibility program.