can be write on glass.windows,paper,led boards features:1. water-based, dry-wipe prescription without toxic, No harmful to skin2. 4g Ink inside it ,with 3mm round and parallel nib, 8g ink inside it ,with 5mm round nib 8g Ink inside it ,with 6mm parallel nib 8g Ink inside it ,with 8mm parallel nib 15g Ink inside it ,with 10mm parallel nib 28g Ink inside it ,with 15mm parallel nib3. high brightness ...