Double fist punch consisting of simultaneous left and right seiken zuki punch. Top of hand faces out to the side. Straight hand, middle finger slightly bent so first three fingers are roughly even in length. Thumb bent and held tightly against palm. Closed fist, strike with bottom of fist.
Hand is open as in nukite , wrist bent back.
Hand held as in nukite but strike is made with inside of hand, a little below the index finger. Index finger joint protrudes slightly and is held firmly in place by thumb. Similar to keiko-ken zuki , but using second finger. Thumb and index finger press firmly against middle finger to hold it in place. Thumb bent and pressed against palm.