OPUS 88 Demonstrator Fountain Pen - Mocha MousseA warm, coffee toned pen with effortless writing comfort The Opus 88 Demo Mocha Mousse is a full sized fountain pen finished in a rich, coffee inspired brown opaque acrylic. It provides a softer, more grounded aesthetic than the original clear demonstrators. Built around a high capacity eyedropper filling system with a shut off valve, it is designed for long, uninterrupted writing. What sets it apart High capacity eyedropper filling system for