Nibs are available in the nib grades shown above. Do a web search for Pelikan Nib Compatibility if you are unsure if these are right for your pen.
New Old Stock Pelikan M200 Fountain Pen Nib Unit, You Choose the Nib Grade!
Lines and Grinds: A Guide for Choosing and Customizing Your Nibs
How to Choose a Fountain Pen
How to Find the Right Nib for your Handwriting Style - Goldspot Pens
The Best Fountain Pens for Every Budget
LAMY Safari Fountain Pen - Charcoal Black - Left-Handed Nib
How to Choose a Fountain Pen Nib - Must Have Stationery
Picking a Workhorse: How To Choose A Fountain Pen for an
Video - How to Choose a Fountain Pen Nib
Sailor 14k nib (right) vs Sailor 21k nib (left). Which to choose
Why are Montblancs so Special? Let's Begin with Meisterstück
Choosing the right Montblanc nib sizes - don't get it wrong again
How To Write With A Stub Nib (Fountain Pen 101)
Pen Trends: Dip Nib Mania - The Well-Appointed Desk
Fountain Pen Types: A Guide to Nib & Filling Systems - Dayspring Pens