0.5mm. Comfort grip. Super smooth. Longest lasting. Refillable. No. 1 selling gel pen (Source: No. 1 selling gel pen, 2010 A.C. Nielsen). Archival safe. Acid free ink. Retractable gel ink rolling ball. Discover writing perfection! Smooth writing & smear proof: Featuring Pilot's unique gel ink formula. Longest Lasting Gel Ink Formula (Independent ISO testing results of top selling branded gel pens on file with Pilot Corporation of America): Writes longer providing exceptional value. Comfortable Rubber Grip: Contoured design fits your hand. Refillable for Continued Use: Use the G2 refill. Made in Japan.
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