Description Peter Bock Fountain Pen Nibs – 5mm or 6mm Bi-Colour Left Handed Nibs Handwriting is a form of art, so to achieve the finest handwriting – A Fountain Pen is your best option. Bock is a well-respected name in the industry and their products represent high-quality and great value. Bock fountain pen nibs stand for precision and quality, and rank amongst the most prestigious in the world. Please chose from either #5 or #6 size nibs Size 5mm (5#) will fit Fountain Pens like the Baron, Gents Classic, Jr Gents, Jr Majestic, Omega, Sedona, and Jr Statesman pens and the size 6mm (6#) will fit Fountain Pens like the Roman Harvest, Gents and Statesman pens.