This is a 6 piece combination internal and external thread repair kit
made by NES thread repair.
This set has the external capacity of 5/32" to 1
1/2", and an
internal capacity of 5/16"-1 1/4". This set of internal and
external
tools will 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.