Tool Kit: Package contains 6pcs different tools, acrylic rulers, crochet hook and knitting needle gauge, yarn tool and other tools. WPI Specification: Quickly determine the WPI rating by counting the number of yarn wraps per inch or laying the yarn along the black strip find a match. Angle Gauge: Align the yarn with the vertical line and slide it over the gauge to find the degree line that best matches the twist angle to help you measure the twist angle. Convenience: Convex notches are used to fix on the spinner to avoid yarn unraveling. Round hole can be paired with gift chain and lobster clasp, easy to carry or hang anywhere you want. Multifunctional: Made of high quality acrylic, clearly marked and multi-functional, you can quickly determine the needle number, WPI and yarn weight. A perfect multifunctional sewing and knitting tool for everyday life. Colour:Transparent Material:Acrylic Package Contents: 6 * Acrylic Rulers Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.