Our largest size is a generous 14" x 27" unit - nearly twice the size of most standard heating pads. Finally, a product that provides an area of heat therapy large enough to cover the entire spinal area, the length of a hip and leg or all across both shoulders, to effectively relieve pain and relax all the associated muscles , not just one small, isolated point. Our #1 Seller Heating Pad Features: Size: 14 x 27 inches Designed for Back, Hip, Leg, Shoulders Simple one-touch control features auto-off timer New Design - Simple one-touch control features auto-off timer. Produces intense moist heat without adding water. Fast-acting therapy relieves pain and stiffness for hours. Max temp: The pads cans run between 150 to 165 degrees F. Turns off automatically after 25 minutes. Made in China Why Thermophore? To make the Thermophore Heating Pads more efficient, we have positioned weights to cause the Thermophore packs to conform to body contours. This reduces air spaces between the Thermophore hot pack and body, so more heat is transmitted to the body tissues. Ordinary stiff plastic heating pads leave air pockets, which result in an uneven transfer of heat. Why not just buy an ordinary heating pad, instead of a Thermophore? An ordinary heating pad is not hot enough to provide the same level of comfort and pain relief as the Thermophore. Thermophore Heat Packs are hot fomentation products and are viewed as a medical device by medical professionals. An ordinary heating pad will keep you warm and help you begin to relax, but it will not penetrate deeply into tissue and will not be as effective as a Thermophore Pack. If you suffer from pain that interferes with your life or keeps you from getting a good night's rest, you will be grateful that you invested in the comfort, pain relief and relaxation of a genuine Battle Creek Thermophore product Why Moist Heat? Moist heat tends to penetrate better because the water molds to the body and provides better heat transfer to the body. Moist heat has been shown to penetrate 27 times better than dry heat.