General purpose crayon stick marker is made for a variety of industrial applications. It writes on most dry or wet surfaces (except on wet glass). Waterproof and highly fade-resistant on most non-porous surfaces and is easily applied on smooth and rough surfaces. Marking surfaces include: PVC, tin, iron, wood, concrete, aluminum and glass. Removable from most non-porous surfaces only through friction caused by hard rubbing. Working temperature range: 14°F to 122°F (-10°C to 50°C) Available colors: Red, Yellow, Black and White. Packed 10 pieces per shelf box. 15 mm diameter x 125mm length (5/8" diameter x 5" length) Will fit in most generic lumber crayon holders for frequent use.