For Athearn Genesis F45/FP45 locomotives, the UFIT-27D9-RC1 and UFIT-27D5-RC1 Rectify systems drop right in. Choose one speaker in either the front or rear location or load both spots for maximum power and output. Both the 9mmH 27D9 and 15mmH 27D5 systems fit either or both locations on the F45. The FP45 requires the 9mmH 27D9 in the rear location to clear the radiator shroud. The long tabs of the stock PCB do interfere with the front speaker a bit, though using the 9mmH UFIT-27D9-RC1 allows the PCB to sit over the speaker without interfering with shell placement. PCB-style decoders such as Loksound Direct and Tsunami2 PNP are not impacted at all.
The speakers come fully assembled and tested.