1,double board or single board. 2,the size is alterable. 3,used other wood which we have 4,best price Steam RoomSpecifications: FunctionBF 330Control system,Adjustable temperature,FM radio,CD connection,Telephone receiver,Steam bath,Ozone, Top light,Wall lamp .Water massage,Foot massage,Cold and Hot water inlet,Cold and Hot,Top shower,Acupuncture nozzles,Movable shower,Exhaust fan.Voltage :220~ ...