BIO-50002 Size: Large / Extra Large Features: -Proudly manufactured in the USA.-Lumbar support.-Material: Neoprene and coolmax lining.-Allow for a cooler fit.-Ideal for back pain and provides extra support.-Support contains 9 concentric circle magnets.-Adjustable straps for more or less tension.-Magnetic fields: 9.-Gauss: 500 Per magnet.-Small / Medium fits waist sizes 24" - 30".-Large / Extra Large fits waist sizes 31" - 40". Options: -Available in Small / Medium or Large / Extra Large sizes. Dimensions: -Small / Medium dimensions: 9.5" H x 33.5" W x 0.25" D.-Large / Extra Large dimensions: 10" H x 43" W x 0.25" D.