This is a Rectify Series drop-in speaker system for Intermountain SD40-2 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 speaker uses the factory mounting screws and no modifications are needed to replace the factory speaker.
 
The speaker comes fully assembled and tested.
 
Dimensions are: 12mmH x 18mmW x 40mmL
 
VIDEO: https://youtu.be/-n2UGByaoKY