Polyurethane is available with different levels of stiffness, hardness or densities. Examples for such materials are:
p ɑ l ɪ j uː ɹ ɪ θ eɪ n WORD_BOUNDARY ɪ z WORD_BOUNDARY ʌ v eɪ l ə b ə l WORD_BOUNDARY w ɪ ð WORD_BOUNDARY d ɪ f ɹ ə n t WORD_BOUNDARY l ɛ v ə l z WORD_BOUNDARY ʌ v WORD_BOUNDARY s t ɪ f n ə s WORD_BOUNDARY h ɑ ɹ d n ə s WORD_BOUNDARY ɔ ɹ WORD_BOUNDARY d ɛ n s ɪ t i z WORD_BOUNDARY ɛ ɡ z æ m p ə l z WORD_BOUNDARY f ɔ ɹ WORD_BOUNDARY s ʌ t̠ʃ WORD_BOUNDARY m ə t ɪ ɹ i ə l z WORD_BOUNDARY ɑ ɹ WORD_BOUNDARY