Colantotte MAG Tank Top The "Tank top" has been upgraded with softer materials and improved magnetic adhesion. Made from highly absorbent cotton with flat, seamless stitching, the design is gentle on the skin. The 3D waist design with a unique switching pattern enhances magnet adhesion. reducing strain on the shoulders and back. 18 of 130 millitesla magnets are arranged in alternating north and south poles from the upper shoulders to the back, help relieve shoulder and back pain by improving blood circulation, easing stiffness, and enhancing muscle flexibility. Number of Magnets: 18 x of 130mT (1300G) permanent Ferrite magnets Material: 7% Polyurethane, 93% Cotton Japan Medical Certification: 221AGBZX00161000 Sizes : S: (Height) 155-165cm , (Chest) 80 - 88cm (Approx.), M: (Height) 165-175cm, (Chest) 88 - 96cm (Approx.), L: (Height) 175-185cm, (Chest) 96 - 104cm (Approx.), XL: (Height) 175-185cm, (Chest) 104 - 112cm (Approx.)