Quick dry and strong adherence ink. Can write on most surface. Low odor ink, recap tighten after use. For use in schools, offices and home. Tip: Strong Acrylic tip suitable for smooth surface like glass or cartons & endurance quality for wooden crates and boxes. Form and Grip: An attractive design with clip on cap, wide base (if someone rests standing) and appropriate width at the gripping point. Ink and reserviour: At per or better writing length than peers good for glass, plastic, metal etc. Refillable: Unique backend unscrewing mechanism. Just pull open cap Place at backend unscrew the plug & drop ink in the reserviour.