Amazon.com : Ackerman Pens Super Sketch Piston Filler Demonstrator Fountain Pen, uses any ink, slip nibs and feeds in and out *note: pen will be dark gray, not black as pictured :
Aurora 88 Demonstrator LE Fountain Pen (#1580) - Gold Trim, 18k Medium Nib (Excellent +, Works Well) - Peyton Street Pens
OPUS 88 KOLORO DEMONSTRATOR FOUNTAIN PEN REVIEW | The Pencilcase Blog | Fountain pen, Pencil, Ink and Paper reviews
Aurora Optima Demonstrator Fountain Pen - Red - Chrome Trim - Pen Boutique Ltd
Sailor 1911L Demonstrator Gold Trim Fountain Pen | Pen Heaven
Opus 88 Demonstrator Fountain Pen - The Goulet Pen Company
Pelikan M800 Demonstrator Fountain Pen – Traditional Chinese – The Nibsmith
Aurora 88 Black Demonstrator Fountain Pen - Sold Out Editions
Fine Writing International Fenestro Fountain Pen - Demonstrator Silver – Yoseka Stationery
Demonstrator Fountain Pens - The Goulet Pen Company
Opus 88 Omar clear demonstrator fountain pen - Fontoplumo
Sailor Pro Gear Fountain Pen - Transparent with Rhodium Trim - Anderson Pens, Inc.
Pelikan Tradition Series M200 Clear Demonstrator Fountain Pen Extra Fine Nib-Montgomery Pens Fountain Pen Store 212 420 1312