StairMaster Pair of TwistLock Adjustable Dumbbells (100-Pounds) Fast: You never have to take your hands off the handles to change the weight. Just dock, twist and go! Simple: The highly visible weight selection windows clearly show the selected weight Compact: Patented design delivers the most compact adjustable dumbbell available Safe: Weight changes can only be made when the handle is in the cradle Design: Contoured, soft grip handles and Aluminum cradle deliver unmatched quality