Now have active dynohub powered lights on 3 bikes, better than a passive reflector..
When in NL long ago I bought a tubular plastic ring of reflective material with a wire through it,
It laced thru the spokes , inside of the tire, above the rim, so unlike the tire sidewall reflective ring,
it did not get cloudy from braking and road dirt.
I am doubtful its made any more..
......