The small Heating Pad uses, 40mm Jade stones, and they are green in color…
The Iso-wrap Heating Pad used, 32mm Jade Stones, and they are green in color.
The Ultra Back and Neck, used 32mm Jade Stone on the outside 3 column and the center two columns use alternating 40mm Tourmaline( Black color) and 40mm Germanium( brown color) .
