Adapts common 1" x 8tpi faceplates & chucks to 7/8" x 14tpi lathes including Beaver Rockwell. 42mm flats accept & Maxwood 5147 wrench Adapt common 1" x 8tpi faceplates and chucks to 7/8" x 14tpi lathes (Beaver Rockwell, etc) 42mm Flat spots cut on back spigot for easy removal from lathe Brand recognition - is a brand you can count on for quality!