Reddit reviews BriteLeafs Far Infrared Therapeutic Rechargeable Cordless Pain Relief Heating Pad/Heating Wrap - Cordless, Rechargeable, Portable, Heat Lasts 2-3 Hours (24"x8")

Safe and simple to use. Cordless, Portable and rechargeable that provides mobility. You can use it anywhere in your home, office or outdoor. 2 temperature settings: Low & High. Long hours of operation ( 2-4 hrs: depending on temperature setting). Flexible velcro straps extend up to 70 inches for a comfortable fit around the pain site. Soft plush heating material ensures contour and comfortable fit.Far Infrared’s superior heating efficiency enables users to use a lower heating temperature and penetrate deeper into the muscles and bones, optimizing its therapeutic benefits.Use it to relieve back pains, shoulders pains, stomach aches, cramps, sore muscle, arthritis, and any other discomfort where heat can be use to treat it.Far-infrared carbon heating fabric in the middle layer can release far infrared wave, distribute heat and infrared wave evenly.For replacement battery, see the link: https://www.amazon.com/dp/B01M0YSW2P