This is a 2-56 Die from K&S Engineering.

FEATURES: A must for the scratch builder, modeler, etc.
Rethreads 2-56 thread pattern
Intended for use on K+S Aluminum and Brass Stock

INCLUDES: One 2-56 Die

REQUIRES: Die Handle (K+SR1220)

SPECS: Thread Pattern: 2-56
Diameter: ??" (19mm)
K&S
Part K+S417