An internal submerged heater made out of marine aluminium is an ideal choice for hot tub heating.All Kirami hot tub heaters are manufactured in our own production facility out of high-quality AlMg3 marine aluminium, which boasts excellent thermal conductivity. Each and every one of our hot tub heaters is pressure tested before going on sale.A simple and traditional internal heater placed inside the hot tub. Since the heater is made out of marine aluminium, it also tolerates seawater and does not need to be rinsed with fresh water after use. The SUB LT has a slightly lower power output than the SUB heater. The heater has a metallic silver finish and a stylish wooden fire box door handle. 120mm chimney is suitable for this heater.