Yes, onion savers do an exceptional job of helping preserve your full or cut onions. Airtight sealing and its shape prevent moisture from getting in, which helps cause odor. Plus, some come in an onion shape with fun colors, making it very easy to identify in a cluttered refrigerator. This makes it a winner in our book. Onion savers are manufactured with a wide variety of materials, including plastic. There are also choices for onion keeper, ceramic and silicone.