About this article Effective Relief: 28 sewn-in magnets placed around the brace provide powerful, even relief from pain and discomfort in the knee area. Two sizes available: To determine size, beat your knee to 90 degrees and measure from the back around the kneecap. Standard fits 18 inches (46 cm) and large fits 26 inches (66 cm). Easy to adjust, non-slip design: wraparound design with hook and loop closure, it will adjust to your knee size. Additional support straps allow you to adjust the desired support and prevent slipping. Powerful Magnets: Each hand-washable support contains 28 magnets that surround the knee with magnetic well-being. Manufacturer rating of 4000 gauss, surface gauss of 600 gauss for each magnet. Polarity: North-Negative (-) Absolute Comfort: Our brace can be worn comfortably for long periods or overnight to give you long-lasting relief from knee pain and health problems.