Our WPI Tool is a handy device for all fiber artists who want to measure their fiber's WPI. Increasingly, WPI is being used by designers and yarn manufacturers when specifying their designs or yarn characteristics. Two yarns that have the same WPI can be exchanged. This is important if you are trying to substitute one yarn for another for a given pattern.         View WPI Video   (at end of Knit-Kard video)   Our WPI Tool: Is made from birch hardwood which has an oil finish applied Measures 5" in length x 5/16" diameter (Yarn Guide knob measures 5/8") All markings are laser etched into the wood and will not wear off. There are markings for up to 3 inches which allows you to calculate a more accurate average WPI on certain hairy yarns. There are also 1/2 inch marks. A special yarn guide knob is used to hold your yarn in place while measuring the WPI. A special WPI Knit-Kard™ comes bundled with the tool in a ziplock bag. The Kard tells the user how to use the tool and provides a useful WPI chart for 6 different weights of yarn. We are the leading worldwide provider of WPI Tools. We have sold over 20,000 tools in the last few years. Why do knitters and spinners prefer our unit? It is made from Wood The ruler is laser etched and will not wear off The tool is highly engineered and ergonomic Our copyrighted WPI Knit-Kard™ is included  It is made in the USA It is the best WPI tool on the market It is priced right at $9.99 Buy a WPI Tool Kit here for $9.99