as you can observe on fig3 the base consists of two parts the front one number 2 and the rear part number 1 fastened together by two hinges number 3 to insure the solidity of the apparatus both parts are made of two slabs of cedar wood number 4 and between these two slabs is included a base of plywood number 5 the base is covered by a mattress so as to provide a confortable treatment for the back the mattress show at fig4 the only sauna mattress to include radiating strips number 8 the mattress is conceived of many different materials the exterior is made of leather number 10 the interior is made of radiating strips diffusing infrared and radiants number 8 of radiating felt number 9 and of ordinary felt number 7 these felts results in a uniform diffusion of the radiants and the conservation of the heat the unique conception results again in a uniform treatment of the back in comfort security and beauty the mattress covers completely the base of the chest to help maintain the beauty of the cedar wood and facilitate the cleaning of the apparatus for comfort a head rest number 11 is added to the mattress the front chest fig5.