The lightest breeze will make them spin. Cleverly made by having many strips of wood threaded onto a central axis. In this design we have left the wood in it's natural state. Leave plain or have fun making your own design. They are delivered flat and you simply 'twist' them, one section at a time into the desired shape. There are two ways of doing this - one with a full double helix and one with a single helix. You can vary the effect depending on how far you open up each section. Please check the dimensions given carefully to access if this product is the correct size required.