The Shimano SW-R671 are a 2-button TT/Tri shifter set with built-in E-tube wires. It is non-branded shifter meaning it is designed to be compatible with Dura Ace 9070 11sp and Ultegra Di2 6770 or 6870 10 or 11 speed. These shifters plug into 3-port EW90-A or 5-port EW90-B cockpit junction box. Can also be used with Ultegra Di2 in a TT/Tri setup without Ultegra Di2 levers using SM-JC41 between the shifters and the handlebar junction in lieu of the 5-port Shimano 9070 junction box.