Valve action marker. Durable acrylic nib for the most demanding environmental conditions: surface temperature from -10° up to + 145°. Marks on dark surfaces where traditional markers would not be easily visible. Can be used on rough, dirty and greasy surfaces. For use on concrete, black pipe, aluminium, PVC, steel & stainless steel, rubber and tyres. 10 seconds dry time. Water and UV resistant markings. Permanent markers. Markings last up to 6 months. Metal barrel for construction site durability.