Pōhaku puka ku'i 'ai. Ring pounder for food. This ku'i (pounder) is worked from porous volcanic pōhaku (stone) into a semi circular stirrup shape that is distinctive to the island of Kauai. It has a flat ovoid base and a central hole through the middle which provides grip. The pōhaku puka ku'i 'ai is dark grey in colour and heavy in weight.