Authentic 3M reflective spoke clips. Comes in a pack of 8.
Clips on rather easily to the spokes. Not for flat bladed spokes though.
Slightly loose, but it does not move about when cycling.
As seen without flash from the camera
With flash! The view that cars see when you go past on the zebra crossing. The words on the Schwalbe tires are also reflective.
Very simple to install, but really improves visibility at night, especially when the wheels are spinning! Adds practically no weight at all. They clip on securely and don't move about or make any noise when cycling. Looks better than traditional rectangular spoke reflectors. Why not add them to your bike?