STAEDTLER 314 3 Lumocolor Permanent Pen, Bold Line Width, 1.0 2.5mm Blue (Box of 10)

Universal pen for use on overhead film and almost all surfaces Dry safe - can be left uncapped for days without drying up (ISO test 554) Good smudge-proof and waterproof qualities on almost all surfaces Broad line width approximately 1.0/2.5 mm Universal pen for use on overhead film and almost all surfaces Blue ink Broad line width (approx. 1.0 or 2.5mm) DRY SAFE ink - can be left uncapped for days without drying up (test ISO 554) Excellent smudge-proof and waterproof qualities on almost all surfaces