Description High Quality Precision ER20 Collet Adapter. Concentric run out within 5 microns Suits our 3" (75 mm)/ 4" (100 mm) Rotary Table. (** Rotary Table is not Included in this Price, please note. Picture is just to display) The base plate is M6 drilled in a manner that it can fit both 3 as well 4 slots table. Supplied with Appropriate 3 Pcs T-nuts The base plate has a spigot extension to guide into the center of the table in order to achieve higher accuracies.