The ITO interchangeable needles are made of dark "Koshitsu" bamboo. For the needles, only the best Japanese bamboo is selected and carefully processed to obtain a warm touch and smooth surface. The bamboo for the dark needles is stored for up to 10 years and additionally steamed. This makes the bamboo very hard and prevents warping which may occur when knitting with light bamboo needles due to the warmth of the hands, especially with smaller needle sizes. The needles are accurately manufactured on modern machines, hand polished and treated with wax for a refined surface. The ITO premium needles are manufactured sustainably in a traditional workshop in the prefecture of Nara.