I can get the brand you showed on line, but think I'll rather make my own - it seems to have a lot of additives and sugar is the first ingredient:
Ingredients:Water, Sugar, Soy Sauce (Water, Soy Bean, Salt, Wheat, Colour E150a, Glucose-Fructose Syrup), Salt, Oyster Sauce (Water, Sugar, Salt, Oyster Extract, Modified Corn Starch, Colour E150a), Yeast Extract (Yeast Extract, Water, Salt), Tomato Paste, Black Pepper Powder (4%), Dehydrated Garlic, Modified Corn Starch, Soybean Oil, Colour (E150c), Acid (E330), Flavour Enhancers (E631, E627).
Far as I can deduce from googling home-made recipes its basically a mix of soy sauce, oyster sauce, and black pepper plus some sort of sweetener.