This jig is necessary for drilling out broken exhaust studs on EPW cars with 1/4"-26 BSF screws.  This jig is installed on 3 existing studs using the the black guides and the included BSF nuts, then use the 4th black guide to locate and drill the broken stud flush with the included 1/4" drill. Replace the black guide with the gold guide and drill the broken stud through with the included .208" tap drill.
The jig should be removed and the hole should be cleaned and inspected.  The existing thread may be able to be pulled out with pliers.  If not, the jig can be re-installed and the hole retapped through a black guide using the included 1/4"-26 BSF tap.
This jig is based on the design by Norman Geeson as posted on KDA132.com.  His instructions will be included with purchase.