The Delta Limited Edition Clear Demonstrator is available in limited quantities, only 88 pieces worldwide. The transparent resin barrel reveals the push-button filler so you can watch the press bar compress and fill the clear rubber sac with ink. Delta recreated the button-filler system that holds a special place in fountain pen history – it replaced the lateral filler in use since the turn of the 20th century. The Delta Demonstrator has a solid black resin cap with solid gold accents and features an 18K gold nib.