These are the ones we use & like. Three thin, strong, nesting, plastic levers from Germany. They take up no space and if your tires fit tight to the rim, they'll save the day.
How to use: Insert all three, each about 4 inches apart. We need a video. It's easy. These are the best. These are the best I/Grant have used, and I've used at least thirty styles over the decades.
Think you got a defective Schwalbe tire?