Bundle of 4: Has 2 leg bundles that measure 2"W x 40"L and 2 arm straps that measure 2"W x 26"L + carry bag, making it a complete set for bite training. They are designed to provide excellent blood flow restriction to the target muscle through the working limb. These blood-restricting bands reduce oxygen supply to the muscles to pre-fatigue slow-twitch fibers and reduce their response to exercise load.Factors that increase muscle growth: Studies have shown that training can increase muscle protein synthesis, expression of NOS-1 and mTOR signaling, leading to increased muscle growth. Research has also shown how using a tourniquet during training can promote muscle growth and enhance muscle-gain potential by lowering myostatin levels. Faster lean muscle and great tone without lifting weights: Occlusion training bands result in very low load hypertrophy (usually 10-30 percent of 1RM). When applied to the working limb and combined with a load of 10-30% of 1RM (lots of repetitions and very low rest periods, before exhaustion begins), results are often close to those achieved with 80% of 1RM. In fact, the Ischemic Band delivers lean muscle and amazing sound with ease and without the need for hard lifting. SUPER STRONG AND SUPER COMFORTABLE BANDS: Equipped with super elastic straps, quick release buckles and elastic loops to keep slack The PRO Package training straps are easy to fasten, easy to remove after a workout, and very comfortable on the working limb. Each package, order comes with 4 tourniquets for occlusion. If you use a bicep band or thigh band, it will keep its shape and elasticity. Note: Barbell not included