1,double board or single board. 2,the size is alterable. 3,used other wood which we have 4,best price Steam RoomSpecifications ... 330Control system,Adjustable temperature,FM radio,CD connection,Telephone receiver,Steam bath,Ozone, Top light,Wall lamp .Water massage,Foot massage ... 162KG N.W. 182KG Transportation20GP 9pcs 40HQ 22pcs 4KW outdoor steam room used for many people