Embed Notice

@mhoye They're tubular clip-on spoke reflectors. There's a length-wise narrow gap that you squeeze the spoke through and then they stay in place on the spoke (well, in theory, in practice some of them sometimes slide up and down as the wheel turns, which is why some of my spokes have two on them). A 36-pack is ~$20 online.

They do get grungy & less reflective over time if you ride them in rain, winter slush, etc etc. You can take them off to try to clean them, but it's not a complete fix.