Starrett PT28314 Collet Adaptor for 827 Series Edge Finders This is a timesaving accessory for edge finders It allows quick installation and removal of the edge finder, eliminating the need for collet changes on bridgeports and similar machines It can also be used with any other attachment with a 3/8" post The progressive steps are: 1/4", 5/16", 3/8", 1/2", 5/8", 3/4' and 1" Step depths vary from 0.100" to 0.200" Time saving accessory for 827 Series Edge Finders Eliminates the need for collet changes on Bridgeports and similar machines Can also be used with any other accessory with a 3/8-Inch post Progressive steps are: 1/4-Inch, 5/16-Inch, 3/8-Inch, 1/2-Inch, 5/8-Inch, 3/4-Inch and 1-Inch Step depths vary from 100-Inch to 200-Inch