4" 45 Degree Elbow "Pair". 26GA Black Stainless Single Wall Exhaust Elbow "Pair" Use with this type of pipe we sell. https://flameinnovation.com/product/1-ft-black-stainless-single-wall-exhaust-pipe/

Single wall pipe is not normally meant for install inside.  For example, you need to keep clearance to combustibles at top of mind. https://www.selkirkcorp.com/en/product/saf-t-pipe This is an example of types of pipe available.  We carry a different brand, but it is essentially the same thing.

Single wall pipe isn't always the best choice for sure.  Subsequently, not always is double wall pipe either.  Every install is different.  We want you to use the safest pipe available.  That is double wall pipe that is insulated. Especially for going through walls or ceilings. Single wall pipe is an absolute no when you go through a wall or ceiling. 45 Degree Elbow "Pair" is used as a single wall installation maybe in a wall tent?

Are you installing in a Yurt? Or possibly a dome home or wall tent?  Some of the types of installs it is OK but you need to know ahead of time what you need to be safe.  We recommend a phone call for a little advice before purchasing your install package. If you are in a wall tent, you lose a lot of heat through a single wall pipe, but sometimes you need that heat loss to help with heating your space.  In conclusion, your pipe selection is very important in more ways that one.