OEM factory original cooling air filter for the E-2 (e SERIES™) Rainbow system. This filter has made several changes over the years and could look different than what you currently have. Original version has four legs on the bottom that have been removed in the revised design.
The new design has a soft gasket on one side. This gasket side lays over the existing motor wires without fear of damage.
Some versions have R10510, R7289, and R7288 stamped into them. This item is the current factory replacement.
The bulk item number for this is R12096B. Some websites list this part number for a single item which is incorrect.