Bowflex SelectTech 552 Adjustable Dumbbells (Pair)

Each dumbbell adjusts from 5 to 52.5 pounds; adjusts in 2.5-pound increments up to the first 25 pounds
Lets you rapidly switch from one exercise to the next
Combines 15 sets of weights into one, using a unique dial system
Eliminates the need for multiple dumbbells cluttering your workout space
Two year warranty on weight plates and parts