The purpose for this was the connect two bathroom extractor fans (two bathrooms back to back with ceiling extraction fans). 4 inch flexible vent hoses merged to a single flexible hose to the outside. Use zip ties but you could use hose clamps. I did print this in PLA Pro, which is probably a bad idea due to heat in attic. Recommend PETG or ABS.
The author marked this model as their own original creation.