For Athearn Genesis F45/FP45 locomotives, the UFIT-27D1-087 and UFIT-27D4-087 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 10mmH 27D1 and 14mmH 27D4 systems fit either or both locations on the F45. The FP45 requires the 10mmH 27D1 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 10mmH UFIT-27D1-087 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 speaker comes fully assembled and tested.