The Shimano SW-R671-L is a left-side electronic bar end shifter specifically designed for time trial and triathlon bikes. It features a two-button interface that allows riders to control the front derailleur smoothly and precisely with minimal effort, using Di2 electronic shifting technology. Compatible with 10 and 11-speed Shimano Di2 systems (excluding 7970), this shifter integrates into the E-Tube system and is typically installed on TT handlebars or aero extensions with a handlebar diameter of approximately 22.2-24.0mm.

It operates via wired connection (cable length around 620mm), ensuring reliable, friction-free shifting without the need for cable maintenance. This shifter is ideal for triathletes and time trialists seeking aerodynamic, hassle-free gear changes during races or training. It weighs approximately 51 grams for the left unit alone and is made from durable plastic housing. The SW-R671-L allows for gear operation from a second position within a Di2 TT setup, giving riders flexibility for comfort and performance.