This opportunity will result in a five-year firm-fixed-price requirements contract for the items listed in Attachment A, with firm-fixed prices required for each year and each CLIN. Quantities shown are the Government’s Best Estimated Quantities for evaluation only and are not guaranteed purchase quantities. All orders will be issued as priced orders, and offerors should propose the most expeditious delivery schedule for each item in each year. The items require Government source approval prior to award, and competition is limited to previously approved/qualified sources. Offerors should pay particular attention to the requirements-contract clauses covering order limitations, requirements, and transportation-cost evaluation.