ADJUSTABLE WEIGHTOur adjustable dumbbell makes you feel like you have 5 fixed weight dumbbells! Each dumbbell block weighs 1.15lb and our hand weights can be adjusted to 3.4lb, 5.7lb, 8.0lb, 10.3lb, and 12.6lb to meet your customized workout needs! Patent Number: US0D1064131S SAFE AND STABLEAdjustable dumbbells set equipped with security lock, no need to worry about the block being loose during use. And the square design allows the multi-weight dumbbells stable and wont roll randomly, giving you a better experience.