The Healthy Wave Mat PEMF Amethyst, Tourmaline, Jade Far Infrared Chair & Car Seat combines key technologies and several types of crystal into one single mat. This mat features optimal PEMF technology at 7-8hz and up to 3000 mG dynamic field strength and is made of 3 lb of crushed amethyst crystal, 3 of 1" Tourmaline ceramic stones and 6 of 1" natural Jade stones. This Healthy Wave mat is a unique design in that it can be used on a chair, in the car or can be laid flat like a traditional mat. It has a standard North American power plug but comes with an optional car power adapter that plugs into your cars cigarette lighter so you can use the mat in the car as well. Due to the PEMF being included in the mat it cannot be bent other than at the designed bend point and should only be used in chairs, seats or laid flat on the ground.