Compatible w/all Toyostove models, this extension pipe set is for use with through-the-wall installation where the heater is to be located away from the flue pipe. Relocation of exhaust pipe is higher or "up the wall," telescoping length capacity is 61-3/4" to 78-3/4". Must NOT exceed: 1. The total length of extension pipe between the heater and the outside tip of the flue pipe must not exceed 10 feet each for the air intake pipe and the exhaust pipe. 2. Neither air intake pipe nor the exhaust pipe may have more the 3 elbows, counting the elbows at the heater. The air intake elbow supplied with the heater and the integral bends in the flue pipe are not counted as elbows.