This knob fits a switch that move my electrical awning in/out. Hard to describe so it's searchable as there's no markings on the switch, but check out the images to see how it connects/sits inside the switch. It's sort of a special design and it should be easy to see if this knob will work for you as well.

Junior managed to hurt himself on the old and broken one that were in our house when we moved in, so I made a printable replacement in Glow-in-the-dark PLA from Faberdashery so now the knob is easy to find in the evening :)