The One pen differs from person to person. Some use the one for their everyday writing needs, others define the one as their grail pen. If it's important to you, you need to keep it protected with this single pen case. Our trademarked leather Pull-Tag™Penholder allows you to securely fasten pens of different sizes and diameters. Friction of the leather on leather pull tag ensures minimal movement and stability. The leather strap offers an elegant holder to complement and showcase the beauty of your pens.