These are basically giant Ziploc bags. They come in three or four sizes, from about 15″ square to large enough to fit a king-sized pillow. There’s a handy little cut out handle in the top to make carrying them easier. They’re clear, so you can see what’s inside. They seal airtight, so they can prevent or slow many kinds of aging. They’re waterproof, as long as you don’t puncture them. They protect stuff from dirt and bugs. Overall, they’re just really useful.
I keep several sizes of them in my linen closet and garden shed, where they store things like bird netting, and linens. They’re handy for keeping sets of things together, and with reasonable care, they’re reusable, though once in a while the zip closure separates from the plastic. A box of 4 of them costs about $7 bucks.
[Note: These giant Ziplocs were first reviewed back in 2007, and we felt it high time to update the review!--OH]