The 15mm Drill Bit is used with the Drilling Template to drill access holes for KV D8 & MSV DB Domino 8mm Connectors. It has a built-in depth stop and Centrotec shank for use in Festools quick change Centrotec system. (It can also be used in a standard drill chuck.)
This template is included with the Festool 8mm DOMINO Connector Set Systainer KV-SYS D8 . You do not need to buy it separately if you are buying the Kit.
