PowerBlock U70 Dumbbells, Looking at the Stage 1. Part of the Urethane Series; Weight Range: 2 - 18kgs (4.4 - 39.7lbs) per Hand; Replace 15 Pairs of Dumbbells or 279kg (615lbs) of Free Weights; Increments Achieved with the U70 Set: 1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 13, 15, 17, 18kg per Hand; Expandable to 27kg (59.5lbs) and 32kg (70.5lbs) per Hand with the U70 Stage II and III Add on Kits; Warranty: Lifetime Home Warranty, 3-Year Light Commercial Use Warranty