Porsche Design Tec Flex Fountain Pen Steel Black 18k Gold NIB 4046901978068 812566. No longer in production by Porsche, Extremely Rare, desirable, and collectible. Ultimate performance in an instant: the Porsche Design Tec Flex Fountain Pen is a unique expression of the power, ambition and technical perfection of Porsche Design. In motorsports, the flexible, corrosion-resistant and hard-wearing qualities of woven stainless steel are used to protect sensitive electronics. In the Tec Flex series, the same high-tech weave not only lends these pens their exclusive look, but also a distinctive texture that rests easily in your hand. All Porsche Design Tec Flex writing utensils are forged from virtually indefatigable stainless steel.