Rectangular plastic ducts
Plastic ducting of 60x200 mm cross section. It is so flat that it can be installed even into constrained ceiling voids or floors. The plastic ducts are rigid so transitions are needed to change the direction or divide the air flow - bends or T-pieces. This plastic ducting is not insulated. When installed into an unheated space (attic), additional insulation is needed.
Plastic ducts incl. adapters are connected using so called sockets. Ducting is shifted directly into the socket of an adapter. It is not possible to connect two adaptors, there shall always be a duct section inbetween.