This Navy requirement is a firm-price buy for manufacture of the LOWER STEM to specified CAGE/reference-number designs. The contractor must maintain an ISO 9001 quality system, mark per MIL-STD-129, package per MIL-STD 2073, and pass Government source inspection; mercury-free construction is required for submarine/surface ship use. Accelerated delivery is encouraged, and all freight is FOB Origin. The Government intends to add an option for increased quantity exercisable within 365 days at the same unit price, with added items delivered at the same rate unless otherwise agreed. Offerors that are not the OEM must provide an OEM letter/official email confirming authorized-distributor status; records must be retained for four years after final delivery, and award will require bilateral written acceptance.