Graf Von Faber Castell Limited Edition Heritage Alexander Fountain Pen Nib Size:Fine in extreme temperatures which ranges in extreme temperatures which ranges from 30 degree Fahrenheit to 250 degree Fahrenheit and in over greased areas has gone through all the alternation and able to uphold their status by offering finest quality fountain pen refill with conventional process and formulas Graf Von Faber Castell superbly express the personalities of Alexander von Faber Castell with their extraordinary craftsmanship of Limited Edition Heritage” Fountain Pen The pen is made of solid silver and the hand engraved nib of 18 carat bicolor gold