The Uni PX-20 Paint Marker is ideal for marking any surface whether it's inside or out. It is both waterproof and fade-resistant for durable, long lasting results. It has a bullet tip with a nib size of 2.8 mm to produce bold, easy to see lines. It's suitable for use on glass, metal, plastic, stone, wood and more. The oil-based ink is waterproof and fade-resistant with a glossy finish. It has a round, easy to grip barrel. This pen is ideal for heavy duty use and can be used both inside and outside. This marker will deliver shiny gold results.