BUNDLE PACK OF 4: Our new PRO Bands now come in a 2 LEG BUNDLE measuring 2"W x 40"L and 2 ARM bands measuring 2"W x 26"L + carry bag making it the complete set to occlusion training. They are designed to offer superb blood flow restriction to the targeted muscles via the working limb. These Blood Flow Restriction bands reduce the supply of oxygen to the muscles to pre-fatigue slow-twitch muscle fibres and reduce their response to workout loads.INCREASED FACTORS FOR MUSCLE GROWTH: Studies show that training can increase muscle protein synthesis, expression of NOS-1 and mTOR signaling, leading to increased muscle growth. The studies also demonstrate how tourniquets can be used in training to boost muscle growth and enhance muscle gain potential by reducing myostatin levels.QUICKER LEAN MUSCLES AND Excellent TONE WITHOUT LIFTING HEAVY WEIGHTS: The Occlusion Training Bands cause very low load hypertrophy (usually 10-30 per cent of 1RM). When applied to work limbs and combined with loads of 10-30 per cent of 1RM (lots of reps and very low rest before exhaustion sets in), the results are usually close to those obtained with 80 per cent 1RMs. Indeed, the Ischemic bands easily and without hard weight lifting offer lean muscles and stunning sound.EXTRA-STRONG AND SUPER-COMFORTABLE BANDS: Fitted with an extra-strong elastic harness, a fast release can buckle and an elastic loop for keeping the slack in place, the PRO Package training bands are easy to secure, easy to remove as soon as the exercise is complete, and incredibly comfortable on the working limb. Per Package, order comes with 4 tourniquets for the occlusion. If you're using the bicep strap or the thigh band, it will retain its form and elasticity.