Lifecore Corebell 5-55-Pound Adjustable Dumbbell System Adjustable dumbbell system that takes the place of 44 dumbbell sets Easily adjusts from 5 to 55 pounds in 2.5-pound increments Slide-and-lock system securely latches onto weight plates Genuine dumbbell shape and feel with contoured comfort handle Commercial-grade cast-iron plates; 5-year warranty on handle