The Shimano Acera RD-3020 Double Servo rear derailleur offers smooth and precise shifting performance with wide-range capability. Its Double Servo technology allows you to ride challenging terrain with fewer interruptions. Note: not for 11-28T. Features include a Double Servo construction for seamless shifting, versatile performance, and wide compatibility. The max. low sprocket is 40T and the total capacity is 45T.

Using your Shimano Acera RD-3020 rear derailleur is easy. Just shift gears as you normally would, and enjoy the smooth and precise movement. When riding, you'll notice it helps you handle tough terrain better. But remember, this derailleur isn't suitable for 11 - 28T sprockets. For maintenance, keep it clean. Wipe it down after rides, especially if you've been in muddy or dusty conditions. You can also use a light lubricant on the moving parts every so often to keep everything running smoothly. If you notice any issues with shifting, check for loose parts or debris. That should help you get the most out of your derailleur.