Sampo Country Style wood burning sauna heaters come in two sizes. Either size can have an 8-gallon water tank built on, and either can be fed from inside the sauna, or from outside the sauna.

The external-feed option is useful if you have a wood pile outside, or if you would like to ensure that ashes and smoke never get into the sauna. The external-feed heaters have a mouth that protrudes through your wall, so that you can load wood into the heater from outside your sauna. The neck extends 5^3/8". You should build a brick wall around the mouth of the heater.