Designed for a versatile workout, the PowerBlock EXP Stage 2 Expansion Kit pairs with the PowerBlock EXP Stage 1 adjustable dumbbells. This kit allows you to expand the PowerBlock EXP Stage 1 Set from 50 lbs to 70 lbs per hand. VERSATILE WORKOUTS: Sold as a Pair, Ships in one box Expands PowerBlock EXP Stage 1 Set from 50 lbs to 70 lbs per hand Adds 6 additional increments to 50 lb set (55, 57.5, 60, 65, 67.5 and 70 lbs) 70 lb set will now replace 22 pairs of dumbbells Expandable later to 90 lbs with PowerBlock EXP Stage 3 Kit 5 Year Limited Warranty