This is a 2 piece external thread repair kit made by NES thread repair.
This set has the capacity of 5/32" to 1 1/2". This set of external
tools restore inch or metric, right handed or left handed
fastener threads. The floating cutters included in this set are
self-adjusting to any pitch and size within range. With these tools
there is no need for calibration or identifying thread types, and the
set automatically chases good thread sections to repair the damaged
parts. This set is supplied in a blow molded case for easy
storage.