The Laars Heating Systems RA2107500 Combustion Air Blower Assembly is an OEM blower designed to supply controlled combustion air to the burner in compatible Laars high-efficiency boilers and water heaters. It uses a high-pressure centrifugal fan and variable-speed motor to maintain proper airflow for stable, efficient combustion. This assembly is used with Laars NeoTherm 150, Mascot, ... https://www.partshnc.com/ra2107500-laars-heating-systems-combustion-blower-assy