We select the best Canada red cedar for its natural resistance to rusts and insects. Customer could choose the wood burning heater or electric water heater. Ciculation pump, fltrationa system, US Balboa SPA heating and control system, Massage jets, Air Bubble Massage, Ozone system and LED system is valiable. Our standard size is 1500*900mm(for 3-4 persons), 1800*900mm(for 4-6 persons), 2100*900mm(for 6-8 persons).