Embossed AC212CW Air Filter Element Age

[jeffschevelle]

Are there any box print dates on the flaps of the box?

The 8 indentions around the outside edges (top and bottom, with none around the inside edge of the bottom), should make that a later filter design than the one Jason posted. (Subject to the overlap discussion above).

I believe yours was made after they switched the square-holed mesh filters from a diagonal orientation to the horizontal / vertical orientation, because all the horizontal / vertical Square Mesh filters I have ever seen have the 8 indentions top and bottom, while I have never seen a Diagonal Mesh with those indentions on top (and they have 16 on the bottom). Again, the judging manual says that change happened late August or Sept of 1969.