This is a Rectify Series drop-in speaker system for Bachmann Soundvalue E7 locomotives. The rear-mount speaker mounts in-place of the stock speaker. No modifications are needed to replace the factory speaker.
 
If you buy a non-sound unit or decide to replace the factory ECO sound with another decoder, you can choose to install two speakers by installing the BAHO-EUBK in the rear position and the BAHO-EUFR behind the cab. The BAHO-EUFR will not fit if you're retaining the stock PCB.
 
Dimensions:
BAHO-EUBK-RC1: 23mmDia x 8mmH
BAHO-EUFR-RC1: 8mmH x 28mmW x 27mmL
 
The speakers come fully assembled and tested.