SmartCuffs 4.0 are utilized for blood flow restriction (BFR) training and are tailored to comfortably suit either the arm or leg. These cuffs can be wrapped around a limb during physical activity to sustain arterial inflow to the muscle while hindering venous return (venous occlusion). They aid in enhancing muscle size (hypertrophy), muscle strength, cardiovascular capacity, and growth hormone (GH) levels.