The dual point multipurpose marker leaves a permanent mark on most nonporous surfaces. One end is for details, with an extra fine plastic point that won't break down. The opposite end is for broader lines, with a tough fiber point built for heavy use. Waterproof and writes on leather, metal, wood, glass, CDs, plastic, and photographs . Alcohol based cleaners will remove ink from nonporous surfaces. Set Includes 4 colors: Black, Blue, Red, Green.