The Shimano Ultegra RD-R8000-GS is a medium cage rear derailleur designed for 11-speed road bike drivetrains. It features Shimano’s SHADOW RD construction with standard or direct mount type, offering a sleek profile close to the frame to reduce damage risk and improve shifting performance. This derailleur is compatible with LINKGLIDE and HG 11-speed chains and supports cassette sizes ranging from 11-28T up to 11-34T, making it suitable for riders needing a wider gear range. Its total capacity is 39 teeth, matching well with front chainring differences up to 16T. The derailleur uses aluminum material for a balance of strength and light weight, averaging 210 grams installed weight. It incorporates 4 fluorine coated link bushings and both guide and tension pulleys with bearing support for smooth, consistent shifting action. The Hollow B-Axle design enhances stiffness and durability. This derailleur is an excellent choice for road cyclists upgrading their groupset for wider gear ranges or seeking reliable, stable performance with Shimano’s 11-speed road components.