These marking pens produce precise lines of 0.3-mm width and are perfect for marking lab samples, microscope slides, photographic slides, glass and plastic beakers, and plastic sample bags. They write on all surfaces including glass, film, wood, plastic, metal, rubber, and porcelain. The permanent ink dries quickly and is waterproof and fade proof. Unique stainless-steel long leg allows precise writing in a limited space. Instant writing, long storage time, and dry-out prevention are assured by an airtight ring seal cap. Available in opaque black, vivid red, blue, and green.