Groz 4Pc Wriggler Center Finder Set C365 19 S10 blades (x5) Size:9.5 S10 blades (x5) Package Contains: 54" x 32" 3 8 inch thick four part composite with 1 lb Spring tension on the ball of the point permits guiding the point to true concentricity bringing perfect alignment between the work and machine spindle Wiggler with Ball Contact is useful in locating work by first bringing the ball contact against the work and then indexing it to the desired position relative to the spindle Wiggler with Disc Contact is particularly useful in locating work in confined areas such as slots or shallow holes 5mm) Wiggler with Offset Indicator holder is useful for checking run out or concentricity and in checking straightness or alignment of flat surfaces