This opportunity is a total small business set-aside for the manufacture and supply of a BLOCK, PISTON, with a one-year warranty from delivery. The contract will be awarded based on the lowest aggregate total price for the base quantity and an option for an increased quantity, exercisable 365 days after award. Performance requires compliance with ISO 9001 quality standards, MIL-STD-129 marking, and strict mercury-free requirements for submarine/surface ship use. The location for performance is not specified, and no budget amount is provided. The contract is DO-rated for national defense under the Defense Priorities and Allocations System.