ʻO ka poloka haʻalulu he ʻano huahana polyurethane me ka elasticity kiʻekiʻe a me ka paʻakikī kiʻekiʻe, nona nā mea hoʻololi kaʻa.Hoʻohana ʻia ia e hoʻokomo i ka pūnāwai coil o ka ʻōnaehana hoʻokuʻu kaʻa, ka mea nui i ka hana o ka buffering a me ka haʻalulu absorption a pale i ke kaʻa.
ʻO ka hoʻomaikaʻi hou ʻana i ka lepo lepo a me ka anti-kahiko, ke ola lōʻihi a me ke kūpaʻa wela kiʻekiʻe, i hana ʻia me ka polyurethane, ke kūpaʻa aahu, ka ikaika tensile, ka waimaka kūʻē, ka ikaika kiʻekiʻe a me ke kūpaʻa paʻa Paʻa kaʻa.