PowerBlock EXP Stage 1 Adjustable Dumbbells have a weight range of 5-50 lbs and replaces 16 dumbbells in the space of 1. EXP means expandable and you can expand this set later to 70 lbs and again to 90 lbs with optional expansion kits. Powerblock Exp Stage 1 Adjustable Dumbbell 50lb Pair Set 50 Pounds Dummbells. 4.5 out of 5 stars (12) Total Ratings 12, $529.69. Free Shipping. Compare at $575.00.