The Trane BAYFRAME210A is an air filter kit that fits the following air cleaner model:
The Trane Perfect Fit BAYFRAME210A Filter Kit- 21x27x5 contains 1 plastic frame and 1 BAYFTFREXM expandable accordion filter. This Trane Perfect Fit Filter, when assembled, is identical to the Trane BAYFTFR21M 5 inch box filter. This Trane air filter is less expensive to buy and ship than regular 5 inch box filters.
The Trane BAYFRAME210A specifications: