Pica-Dry spare leads. à‰ case of 8 leads: x4 graphite, x2 red and x2 yellow. Technical specifications: For almost all types of surfaces, dry or damp, smooth or rough, dusty or oily, light or dark. Wipe clean with a damp cloth. Pre-sharpened leads. In a sturdy, practical plastic case. Do not expose red and yellow leads to temperatures above +30°C. Diameter: 2.8mm, Length: 125mm. Supplied in a new, sturdy case with much greater rigidity against bending and twisting, which increases the lead's resistance to breakage. Ideal for use on the following materials Metal Plastic Tiles, ceramics Wood, laminate Glass Rough wood (dry) Rough wood (wet) Stone, concrete Tyre, rubber (dry) Tyre, rubber (wet)