Shimano Di2 SW-R671 Shifter Set. These Ultegra Di2 aerobar shifting switches provide easily accessible, incredibly responsive electronic shifts. Simple push-button operation makes the SW-R671 an ideal fit for time trial and triathlon bikes. SW-R671 shifting switches for aero bars - left/front & right/rear.SEIS - Shimano Electronic Intelligent System. Compatible with Ultegra 11-speed Di2 & Dura-Ace 11-speed Di2 groups. Fit extensions with 22.2mm - 24mm outer diameter & 19-22.5mm inner diameter. The item "Shimano Di2 SW-R671 2x11 sp TT Bar-end Shifter Set Aero Bar Left & Right NEW" is in sale since Tuesday, December 11, 2018. This item is in the category "Sporting Goods\Cycling\Bicycle Components & Parts\Shifters". The seller is "benscycle" and is located in Milwaukee, Wisconsin. This item can be shipped worldwide.