What is the pin in the bottom of this nail knot tying tool used

By A Mystery Man Writer

.com : The Knotter HBK Knot Tying Tool, red White Blue : Fly Fishing Tools : Sports & Outdoors

My-Tie Fishing knot tying tool from 3A Outdoors (With Safety Lanyard)

SAMSFX Fast Tie Nail Knot Tying Tool and Loop Tyer Hook Tier – samsfxfishing

How to Tie a Knot in Thread for Hand Sewing - Create Whimsy

Beading Wire Knotter Pearl Jewelry Making Knotting Tool - Temu

EMSK: How to untie a tight knot : r/everymanshouldknow

Loon Outdoors - How do I use the Ergo Knot Tool?

Knotting the Thread - Sarah's Hand Embroidery Tutorials

Tying Tools Gary Borger

Nail Knot Tool & Knot Card Combo – ReferenceReady

Tying Tools Gary Borger

2 for $25.99 – The Knot Kneedle

Fishing Tackle 2022 New, Nail Knot Tying Tool, Fly Tying Knot Tool

SAMSFX Fast Nail Knot Tying Tool 4 in 1 Fly Fishing Clippers Nippers – samsfxfishing

SAMSFX Fast Nail Knot Tying Tool 4 in 1 Fly Fishing Clippers Nippers – samsfxfishing