In the international petroleum industry, crude oil products are traded on various oil bourses based on established chemical profiles, delivery locations, and financial terms. The chemical profiles, or crude oil assays, specify important properties such as the oil's API gravity. The delivery locations are usually sea ports close to the oil fields from which the crude was obtained (and new fields are constantly being explored), and the pricing is usually quoted based on F.O.B. (free on board, without consideration of final delivery costs).