The Department of Defense, specifically the Naval Air Warfare Center Aircraft Division, is seeking to negotiate a sole source contract with Viavi Solutions LLC for the procurement of IFF-45TSL Test Sets. These test sets are essential for supporting Identification Friend or Foe (IFF) transponders, IFF interrogators, and tactical air navigation (TACAN) transceivers for the U.S. Navy fleet. The Government plans to establish a five-year Basic Ordering Agreement with Viavi Solutions LLC, the sole designer and manufacturer of the required test sets, under the authority of 10 USC 3204(a)(1) and FAR 6.302-1. Interested parties should direct their responses to Danielle Russo at danielle.m.russo4.civ@us.navy.mil by the specified response date and time.