Ink Refills For Swarovski Crystal Elements Filled Ballpoint Pen (BLUE-10PCS) The D1 pen refill is a standard pattern used in most multi-function pens and many compact or expanding pens. Made of metal, with a hollow end, it measures 67mm in length and approx 2.3mm in diameter Measure 67.5mm without end cap The refills are not manufactured, licensed, or endorsed by the pen manufacturers referred to. The trademarks of the pen manufacturer are identified only for the purpose of providing refill compatibility information