The pad included with the mat is made with synthetic material. Don't synthetic fibers block FIR?

We include different thick and thin multilayered protectors with the sets that come with the mat. 

They include combinations of synthetic and natural materials to be waterproof, sweat absorbing, washable, yet breathable at the same time. 

All of them are completely permeable to FIR rays, PEMF, and are moderately permeable to negative ions (which enter the body through the skin and not through breathing). 

These covers and pads are not very permeable to red light photons. 

Some customers use the mats without any covering for ion therapy or intensive detox procedures. 

You may put a cotton or bamboo towel or sheet on the mat instead of our protective cover if you need more ions.