The OXO fat separator makes it simple to quickly strain grease out of the gravy. The gray strainer on top pulls out onions, carrots and other vegetables you might have been cooking with the roast. The grease stays in the cup while the leaner part of the liquid rises through the spout. Making gravy is usually done in the last minutes before a big meal when the kitchen is busiest. OXO kept that in mind when developing this gadget. The arched top of this separator protects the cook from hot liquids that could splash over the top of the cup. Also, while most separators are made of fragile glass, this tool is made of sturdy, easy to clean plastic.
This tool is not as elegant as OXO's amazing peeler. The small stopper is easily lost and the tool takes up a frustratingly large amount of storage space in a small kitchen. This tool should also come with instructions to help those who aren't familiar with it.
Though not a necessity, this tool is nice to have, especially if you frequently make gravies. If you serve many guests, buy this 4 cup tool. If you cook for smaller groups, go for this 2 cup version. Keep in mind that you must have enough liquid to cover the top of the spout for this gadget to work correctly.