The Griffin Hook / Hackle Gauge is perfect measuring correct hackle length and hook size.
EP® Trout Fly Tying Gauge– All Points Fly Shop + Outfitter
Whiting Farms Whiting W-100 Hackle Gauge – Bear's Den Fly Fishing Co.
Maximumcatch 2pc Wooden Fly Tying Hackle Gauge Fish - AliExpress
Griffin Hook & Hackle Gauge
Whiting - W-100 Hackle Gauge — Golden Fly Shop
Griffin Montana Mongoose Fly Tying Vise - AvidMax
Wood Hackle Gauge - The Fly Shack Fly Fishing
Flytying: New and Old: DuBois Hackle Gauge
New Hook Hackle Gauge Feather Gauge For Fly Tying Vise Fishing
The Hareline Hackle, Hook, & Bead Gauge was designed to be the ultimate accessory for your fly tying vise. Simply slide the gauge onto the stem of your vise and you will have the ability to measure hackle, hook, and bead sizes within a matter of seconds. This beautifully designed gauge is made of anodized aluminum and is available in your choice of 4 popular colors.
Hareline Hackle Hook and Bead Gauge - Purple
Dick's Sporting Goods Perfect Hatch Hook & Hackle Gauge
Hareline Hackle, Hook and Bead Gauge Anodized Red #310 - Hareline
FFS Fly Tying Hackle Gauge and Hook Chart - Solid Wood - COMBINED
Badger Creek Standard Hackle Gauge, Terra Wood Hackle Gauge - On-Line Fly Tying Magazine and Fly Tying Catalog