The product widely known and marketed in the USA as langostino is the cooked and peeled tail meat of a small crustacean between shrimp and small lobster in appearance.
Large quantities are imported from Chile and parts of Central America. The frozen product is a tasteless, soft-textured item, used mainly as a substitute for lobster meat in recipes that contain more strongly flavored ingredients, such as salads or sandwiches where the mayonnaise and vegetables mask the lack of flavor of the langostinos.
Langostinos are usually packed in 12 ounce bars, polly wrapped and then put into printed cartons for retail sale. Retail business on this item used to be huge, when the product was cheap. They are usual one dozen bars in a box, four boxes per carton, expressed as 4/12/12oz.
To overcome poor plant hygiene and FDA rejections, most langostinos are pasteurized to destroy bacteria. This process requires a thinner bar, so pasteurized langostinos have two 6oz bars wrapped as a 12oz, giving the complicated packing description of 4/12/twin 6oz.
I.Q.F. langos are also available, packed in 6/5lbs bulk for institutional use and 8oz and 16oz retail bags. I.Q.F. langostinos prices are usually quoted per pound, while the bars are frequently quoted per 12oz bar.
Make sure that your price structure is clear when you buy or sell this item. The Chile langostinos is regarded as the market leader, and generally those from other origins sell at a substantially lower price, since the flavor and texture are thought to be inferior. It is worth trying these products and making your own judgment.