PILOT 3+1 RiDGE Pilot 3+1 RiDGE 0.7mm Fine This is a multi-function pen from Pilot. It combines a 0.7mm ballpoint pen with black, red, and blue Acro Ink, and a 0.5mm mechanical pencil. The lifespan of the ballpoint pens is unknown, but they are currently writing normally. I believe the eraser is unused. There is no case.