Herewith Kizuna Duratech D61 Top quality badminton stringing evaluate; Kizuna Duratech D61 premium badminton string by ERR badminton restring Singapore. Kizuna D61 is just introduced in 2019. This Kizuna D61 badminton string as you'll be able to begin to see the gauge is skinny only 0.61mm, but this string ready to offer “hard” feeling.