Don't know it but is a set. Only the two lower nibs are of use....the others are way too fat, and two are for outlined letters.
I have a cheap Manuscrip make with a BBBB that is only good for making Headers and at least one of those nibs is even wider than that.
Look in English Ebay for a 6 nib Osmiroid calligraphy set, if it comes with a pen, it is a cheap feeling pen...one is a sac, so you'd waste money getting it re-sac'ed. How ever the Osmiroid nibs will fit Esterbrooks. I have such a set. All six widths are usable. Still have two Esties too.
You can also get a Lamy Joy/Safari with a 1.5 mm nib, that will write wide enough that you can see what mistakes you make as you learn by copying letters out of a calligraphy book, and you can swap a 1.1 nib in and out of your Safari/Joy.
I was just talking on another post about how little Italic calligraphy is refereed to here....and there is so many great scripts.
Sheaffer made an adequate set, but the Osmiroid is better. I gave my Sheaffer set to my god child, in I had that Osmiroid.
Everyone says poor Mozart dead at only 36. None say poor Mendelson, dead at only 38. His family only allowed him to start at 20, but before, musicians use to come to the Mendelson garden to steal the music of Mendelson and his sister. A good artist also, can still buy prints of his famous Scottish drawings in Scotland.
www.nibs.com/blog/nibster-writes/nibs-germany Info on Bock nibs
The cheapest lessons are from those who learned expensive lessons. Ignorance is best for learning expensive lessons.
Pens/inks/paper on hold for a year....new addiction pocket watch chains.