Contains four 100mT ferrite permanent magnets arranged in Colantotte’s unique Alternating North-South Polarity Orientation (ANSPO™). This layout allows the magnetic force to affect a large area, improve blood circulation, and alleviate stiffness in the worn area. The loop uses operon rubber, so it is easy to put on and take off. Size: M (15cm), L (17cm), LL(19cm) Materials: Magnet: Four 100mT (1,000Gauss) Ferrite permanent magnets are arranged in Alternating North-Sounth Polarity Orientation (ANSPO™) Loop and the others: Natural Stone, Stainless Steel (SUS316L) (the rectangle parts and rondel), Operon Rubber Benefits of Colantotte:- * Relief stiff neck & shoulder * Aids Sports injury recovery * Relief back pain and muscle pain * Reduce fatigue * Mental Relaxation * Increase quality of sleep * Relieve Stress * Improve mental concentration