The Fishpond Firehole Tippet and Leader Gage measures up. If you build or repair your own leaders, the Firehole Tippet/Leader Gage is sure to become one of your most indispensable accessories. Machined from aerospace aluminum, this unique tool measures tippet material and monofilament line from 8X (.004) all the way up to .031 with pinpoint accuracy. It also incorporates a hook eye clean-out pin.