The picture show the "B" style filters, the standard for the 75A-2A and the 75A-3. For reference these filters are 2.12" X .97".

In the past I acquired the X455-KF-0300 Crystal filter. The only difference between the "KF" and the "B" style package is the "KF" has screw studs in place of the plug in studs on the "B". I filed the screw studs on the "KF" package so they would plug in to the 75A-3 socket. The result was a world class CW receiver. It is amazing the selectivity the 300HZ "KF" package crystal filter gives the 75A-3.