Versatile 4-in-1 Adjustable Dumbbell Set (10-90 lbs). Why Choose Our Adjustable Dumbbell Set?. Experience the power of adaptation and the comfort of quality. 4 in 1 Multifunctionality: Convert between dumbbells, barbells, kettlebells, and push-up stands, allowing you to perform a wide array of exercises, including bench presses and squats.