Shimano SE-4S35 is an advanced cycling computer that provides a range of features to enhance your riding experience. It offers both manual and automatic gear shifting modes, allowing you to choose the level of control you want over your bike's gears. The automatic modes, "D" and "Ds", adjust gears based on your speed, while the manual mode, "M", lets you shift gears one at a time. The digital display clearly shows your current gear, speed, and battery level, and it also alerts you when the battery is low.