Here are a couple bottles you might want to keep an eye out for.
[Oyster Flavored Sauce (USA); Nahm Man Hoi (Thai);
Dau Hào (Viet)]
This is a very important Chinese sauce, also much used in Thailand, Vietnam and Cambodia. It was invented accidentally by Lee Kum Sheung in Guangdong in 1888. He founded the Lee Kum Kee company to market it. Today it is made by many companies in Asia and elsewhere, in an extremely wide range of quality, some having very little association with actual oysters.
This sauce must be called "oyster flavored" sauce in the USA because it is made from extractives rather than whole oysters. Lee Kum Sheung's original recipe was made with whole oysters and nothing else, but that method is excessively expensive today.
This is a savory and sweet sauce, very much used all over China for all manner of cooking, from "red cooking" to stir fries, in the home and in restaurants.
In Thailand, it is used in many Thai/Chinese style dishes, usually in "end of cooking" sauces, combined with stock, fish sauce and often lime juice. As in China, it is also used in noodle dishes. Thais consider all noodle dishes to be Chinese, and they are the only dishes Thais eat with chopsticks.
Oyster Sauce should be refrigerated after opening.
More on Sauces & Condiments
Here are a couple bottles you might want to keep an eye out for.