Actually silicon, Ive ordered other cases that claimed to be but then werent. I decided to spend a bit more on this product and avoid buying the cheapest version (my usual temptation! Smaller then you would guess. I prefer a bit warmer tone and this app achieved that easily. Contacted the seller and they said to send them back for inspection and replacement. The low top also makes them easy on and off. Update: bought a size 9 and they fit. First off, yes, its crazy loud! For the price you cant go wrong! incómodos quizás x q sean para orejones.