If they have STI shifters that are 9 speed you should be okay.
This computer was designed by Shimano to further integrate the biking experince. It extends the idea of Shimano's Total Integration (STI) and allows a visualization of shifting and computes a virtual cadence based on your gear ratio and speed. All functions are at the tip of your right thumb with Flight Deck compatible Shimano STI shifters. Featuring current speed, clock, trip time, trip distance, odometer, stopwatch, stopwatch-trip distance, stopwatch-average speed, stopwatch-max speed, virtual cadence, max speed, average speed, lap counter, gear number, gear indicator, gear ratio, current speed to average speed comparison, low battery display. Additionally, model 6501 offers four-bike programming )gearing and wheel size), number of chainrings, and gear size display (e.g., 53x12). Harness SM-6500 is compatible with Ultegra shifter ST-6501 and 105 Shifter ST-5500-C. Harness SM-6500-RS is compatible with levers ST-7700-C, ST-3300, and 4400 (Tiagra and Sora).