Ultegra is the standard for great durable components.  Simply the best bang for the buck.

Features:

• Lightweight 11-speed HG-EV cassette with rigid alloy sprocket carrier for reduced weight and better shifting performance, even under the most demanding gear changes
• Hyperglide EV sprockets have been designed to reduce weight with improve teeth shaping providing accurate shifting and reduced wear
• Wide gear range to meet the demands of all types of rider
• For use with HG-EV chains
• Weight: 212g (11-23)