These are clever. I've been needing these for years but didn't know it! It's a simple concept: take a common bag closure clip used to seal plastic bags to keep moisture and bugs out and add a spout with a cap. The result is you can keep your stuff sealed without having to fumble with zip closures that don't work or else repackaging your stuff. The spout also controls the pour better, so less powdery stuff all over. These also have a handle, which is handy. Wish I'd invented this. I won't take a star off but my one criticism is that wish they had come with instructions. There are instructions with pictures on the Amazon product page, but I'd prefer not to have to look things up.