These are Rectify Series drop-in speaker systems for Intermountain GEVo ES/ET locomotives. More than just a box, the enclosure features Diapasonic Tuning™, which allows the lower frequencies to accurately develop and resonate, clears the midrange of excess resonance and tunes the upper-mid/high response. The speakers use carpet-tape or a touch of adhesive to mount and no modifications are needed to replace the factory speaker.
 
Two rear-mount options are availe:
IMRH-E441-RC1 (early-run replacing the round 28mm speaker)
IMRH-E442-RC1 (current-run replacing the twin-cube speaker)
 
Likewise, you can add two different front-mounted speakers for better horn/bell localization:
IMRH-E44F-RC1 (early-run)
UFIT-9115-RC1 (current-run)
 
The speakers come fully assembled and tested.
 
Dimensions are:
Early-run: 19.5mmH x 18mmW x 43mmL
Current-run: 12mmH x 18mmW x 56mmL
Early-run front-mount: 14mmH x 18mmW x 22mmL
 
VIDEOS:
Early: https://www.facebook.com/scalesoundsystems/videos/312132159549689/
Current: https://youtu.be/J4F3yWOyorg