Shimano ULTEGRA 2 x 10-Speed Dual Control STI Road Brake Lever/Shifter Set
The Shimano ST-6600,(part of the Ultegra group set), is a 2 x10-speed integrated brake and shifter lever. Right(rear) lever: ST-6600 compatible with Shimano 10-speed. Manufacturer: Shimano. Left(front) lever: ST-6600 specifically designed for 2 x(double) drivetrains.
Shimano Ultegra 6600 ST-6600 10 Speed RIGHT/REAR Shifter
A little sticky but fully functional. Could probably use an ultrasonic cleaning for optimal performance.
Shimano Ultegra ST-6600 STI Shifters 10 Speed Double w/ Clamps Excellent
The ST-6600 set was the benchmark for Ultegra’s mid-2000s era — hidden cable routing, a shape that still feels great in the hand, and shifting that holds up decades later. In other words, your Shimano levers will only work with Shimano derailleurs.