Hand forged from 303 stainless steel to resist corrosion 
Ergonomically designed for versatile grips and carry options
Diamond cross section comes to a pyramidal point
Hand filed to break edges on the corners for additional grip comfort
On the Black Quills, these feature a dark surface finish formed by rapid oxidation of hot steel exposed to air--a form of iron oxide. This finish is far more durable than a chemical patina. The dark surface finish is removed on the pyramidal tip, chisel edge, and top corner of the Quill's diamond cross section (which is used for scraping tasks).
 
Quill sizing:
Put your middle and ring finger together and measure the circumference around the widest portion.
If this measurement is less than 4", choose the Slim Quill size.
If this measurement is between 4" and 5", choose the Original Quill size.
If this measurement is over 5", choose the Quill XL size. However, smaller sized hands can still use the Quill XL, it just requires an extra finger to grip through the hook gap portion.
 
Quill Trainers: These are sold as a pair. Both trainers are approximately the size and shape of the Original Quills (standard size)
Blue Quill Trainer is rigid and 3D printed from PRO Series Nylon (procured from MatterHackers). This trainer is printed by G3DPrintables as a solid, rigid structure. The Blue Quill Trainer is best used to practice full impact blows, rakes, and hooks against Body Opponent Bags (or similar) and weapon retention exercises. 
Red Quill Trainer is flexible and 3D printed from Ninjaflex, a specially formulated thermoplastic polyurethane to provide flexibility and longevity. The Red Quill Trainer is printed by G3DPrintables with internal voids at the tips to cushion impact when sparring with a training partner. Ninjaflex material is made in York, Pennsylvania.
Diamond cross section comes to a blunt point.