SS chimney top intake:

This stainless steel Chimney Top Intake frame for the Harman Accentra 52i-TC pellet stove is used on top of the chimney to support a liner cap cut-off plate. This helps the exhaust exit above the intake and allows the installer to use a regular chimney liner cap instead of a co-linear system. These Pellet Stove Parts may be compatible with other manufacturers.