Boncare via Amazon has Boncare LCD Digital Control Extra Large Heating Pads for Back Pain Relief and Cramps with Auto Shut Off Moist/Dry Heat 12" x 24" (Dark Gray) for $12.48
‘clip the 50% coupon on product page – Shipping is free w/ Amazon Prime or on $35+
- Covered by a 3-month money-back guarantee and a 3-year warranty.