Tannus Armour is a tyre liner -
@Racing roadkill has/had their solid tyres.
Cheapo liners sold on
ebay cause friction punctures as they shift a little inside the tyre.
The Armour is thicker, but softer.
It looks a better job, although you need room inside the tyre to fit both it and a smaller cross section inner tube.
Might be a bit tight on a roadie tyre, but should work well on hybrid, MTB, and balloon tyres.
My local bike shop has sold a couple of pairs.
Positive, or at least no negative, feedback so far.
https://tannus.co.uk/armour/