Easy Wood Tools C1000 1" x 8 TPI Threads Wood Turning Lathe Quick Change 4 Jaw Chuck with Zoom Ring, Snap Lock Technology and Stainless Steel Chucking Screw none Made in USA 100% designed and manufactured in the USA Includes two important features: Zoom Ring (ZR) and Snap Lock Technology (SLT) Zoom Ring gives you the ability to open and close the jaw quickly with the just your fingertips Snap Lock Technology allows changing one set of 4 jaws to the next set in less than 30 seconds Includes 1 3/8" Easy Dovetail Jaws for gripping 1 3/8" tenons with overall expansion of 2"