YOU GET BOTH SETS

SET 1

When there Is still some of the head showing

5 Chrome "molybdenum" steel Bits 

Specially made to cut into your Damaged screw or bolt head and grab it

Forcing it to unscrew in reverse and come out of its hole.

WITHOUT damaging the surrounding material or the original screw hole.

SET 2

5 Hardened steel Bits  

When the head has sheared off and nothing to grab hold of.

5 reverse thread Penetrating extractor bits

First drill a small pilot hole into the offending item

Extractors is screwed into the drilled hole. 

Extractors have a reverse thread so you turn them anticlockwise 

Extractor cuts into damaged shaft and turns it out of the hole its in.