NOVA 10051 10 in 1 Chuck Gauge Accessory is an accessory for NOVA Chucks and the general workshop. This handy gauge is exclusive to the NOVA Chuck range. Quickly and easily work out your dovetails accurately. If you use a Chuck, this is an essential accessory. In addition, this useful gauge also comes with a variety of common measurement and gauging functions used in the wider workshop, such as an angle checker for knives, carving tools, chisels and planer blades. Also a diameter gauge, a center finder, a dowel gauge, a furniture angle gauge, a ruler scale and many other functions. Designed by the innovators of the 4 Jaw Chuck for wood turning, Teknatool International - since 1955. Backed by a full replacement 2-year warranty. Call our customer service center toll free on 1-866-748-3025.