It is the full version inside of a JK Flip-Flop. It is good for binary counters and shigt registors. The CLK(CLOCK) is the Middle-Left Button, The J(SET) is the Upper Data, The K(RESET) is the Lower Data, The PRE(PRESET) is the Upper Button, The CLR(CLEAR) is the Lower Button. When the J and K both is a "1", it toggles, used as a TFF(Toggle Flip Flop).
