Baxi Sirius FS 90-105-130-160 Installation, Operation & Maintenance Manual page 22

11.2 connector with c53 type
The kit is used to introduce combustion air from outside the installation area and comprises a hose to be
installed in the mixer body.
Please consult the instructions supplied with the kit.
For air ducts (diameter and length), see the kit manual.
InstructIons pertaInInG to the InstaLLer 912.823.1 - GB
22