The Serenity 2000 dual function Waist Wrap with 34 sewn in magnets provides powerful magnetic & far infrared therapy, Bioceramics, woven into the fabric absorbs body heat and returns it in the form of far infrared energy, The combination provides a very deep penetrating therapy to relieve back aches, Lightweight, breathable material with pocket for cool or hot pack, Hand wash & hang to dry, Small fits waist 18"" - 26"", Medium fits waist 26"" - 36"", Large fits waist 34"" - 46"", XLarge fits waist 44"" to 54"", SKU: SEREN098