The Work Sharp 50° overlay is an additional guide for the WSKTS sharpener that allows you to sharpen knives and tools at a 50° angle.
Work Sharp sharpener accessories - in the store Kolba authorized distributor of Work Sharp brand.
The outer overlay, unlike the factory version, allows sharpening at a 50° angle, creating a softer but more precise cutting edge. The overlay also has guides for sharpening scissors (65°) and serrated cutting edges.
Note that the guide does not fit the Work Sharp WSKTS MK.2 sharpener.