NSWC Crane requires TR-143A Transducers (P/N 7146100-302) for the SP24 Trident Navigation Subsystem sonar used on U.S. Navy and UK ballistic missile submarines, working with TR-333 Hydrophones to improve submarine launch accuracy. The proposed action is a two-year ordering period extension and ceiling increase on an existing firm-fixed-price IDIQ contract with a five-year ordering period. The Government intends a sole-source award to Massa Products Corporation, Hingham, MA (CAGE 88958), citing highly specialized equipment and certification costs/testing that can take up to 36 months. Other responsible sources may submit capability statements, proposals, or quotations, but any decision to change the acquisition strategy remains within Government discretion, and SAM registration is required.