Lifecore Corebell 5- to 30-Pound Adjustable Dumbbells (Pair) Adjustable dumbbell system that takes the place of 22 dumbbell sets Easily adjusts from 5 to 30 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