This Tool Set Is Used Tto Accurately Find The Position Of The Tool Spindel In Relation Tto The Worksurface, Layout Lines, Holes, Slots, Etc.this Set Is A Must-have For Every Toolbox! Finally, A Small, Reliable Set That Tells You What You Need To Know! Includes Handle And 4 Double-sided Accessories: Offset Indicator Holder, Needle Point, Disc Contact (0.1""), And Ball Contact (0.25""). 5 Piece Set Includes 1 Handle 4- Double Sided Accessories Offset Indicator, Holder Needle Point, And Ball Contact