This EnerGel Rollerball Pen Refill 0.5 mm Blue provides blue ink, 0.5 mm point, single refill for reliable everyday writing and refill replacement. It is suited for Pentel BLN75 and helps extend the life of compatible pens or markers. A dependable choice for office, school, reception, home office and commercial stationery supplies, For Pentel BLN75 pen. Sold by each.